New quaternary tellurite and selenite: Synthesis, structure, and characterization of centrosymmetric InVTe2O8 and noncentrosymmetric InVSe2O8

Article abstract of DOI:10.1021/ic200135k

Two new quaternary mixed metal oxide materials-InVTe₂O ₈ and InVSe₂O₈-have been synthesized, as crystals and pure bulk powders by standard solid-state reactions using In ₂O₃, V₂O₅, and TeO₂ (or SeO₂) as reagents. The crystal structures of the reported materials were determined using single-crystal X-ray diffraction. InVTe₂O ₈ crystallizes in the monoclinic centrosymmetric space group P2 ₁/n (No. 14), with unit-cell parameters of a = 7.8967(16) A, b = 5.1388(10) A, c = 16.711(3) A, β = 94.22(3)°, and Z = 4, and InVSe₂O₈ crystallizes in the noncentrosymmetric space group Pm (No. 6) with unit-cell parameters of a = 4.6348(9) A, b = 6.9111(14) A, c = 10.507(2) A, β = 97.77(3)°, and Z = 2. While the centrosymmetric InVTe₂O₈ shows a two-dimensional (2D) layered structure composed of InO₆ octahedra, VO₄ tetrahedra, and TeO₄ polyhedra, the noncentrosymmetric InVSe ₂O₈ exhibits a three-dimensional (3D) framework structure with distorted InO₆ octahedra, VO₅ square pyramids, and SeO₃ polyhedra. Powder second-harmonic generation (SHG) measurements on InVSe₂O₈, using 1064-nm radiation, indicate that the material has a SHG efficiency ～30 times that of α-SiO₂. Additional SHG measurements reveal that the material is not phase-matchable (Type 1). Infrared, ultraviolet-visible light (UV-vis) diffuse reflectance, and thermogravimetric analyses for the two compounds are also presented, as are dipole moment calculations.

Full text of DOI:10.1021/ic200135k

ARTICLE
pubs.acs.org/IC
New Quaternary Tellurite and Selenite: Synthesis, Structure, and
Characterization of Centrosymmetric InVTe2O8 and
Noncentrosymmetric InVSe2O8
Dong Woo Lee,† Seung-Jin Oh,† P. Shiv Halasyamani,‡ and Kang Min Ok*,†
†Department of Chemistry, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Republic of Korea
‡Department of Chemistry, University of Houston, 136 Fleming Building, Houston, Texas 77204-5003, United States
S Supporting Information
b
ABSTRACT: Two new quaternary mixed metal oxide materials—
InVTe2O8 and InVSe2O8—have been synthesized, as crystals
and pure bulk powders by standard solid-state reactions using
In2O3, V2O5, and TeO2 (or SeO2) as reagents. The crystal
structures of the reported materials were determined using
single-crystal X-ray diffraction. InVTe2O8 crystallizes in the
monoclinic centrosymmetric space group P21/n (No. 14), with
unit-cell parameters of a = 7.8967(16) Å, b = 5.1388(10) Å, c =
16.711(3) Å, β = 94.22(3)ꢀ, and Z = 4, and InVSe2O8 crystal-
lizes in the noncentrosymmetric space group Pm (No. 6) with
unit-cell parameters of a = 4.6348(9) Å, b = 6.9111(14) Å, c = 10.507(2) Å, β = 97.77(3)ꢀ, and Z = 2. While the centrosymmetric
InVTe2O8 shows a two-dimensional (2D) layered structure composed of InO6 octahedra, VO4 tetrahedra, and TeO4 polyhedra, the
noncentrosymmetric InVSe2O8 exhibits a three-dimensional (3D) framework structure with distorted InO6 octahedra, VO5 square
pyramids, and SeO3 polyhedra. Powder second-harmonic generation (SHG) measurements on InVSe2O8, using 1064-nm radiation,
indicate that the material has a SHG efficiency ∼30 times that of R-SiO2. Additional SHG measurements reveal that the material is
not phase-matchable (Type 1). Infrared, ultravioletꢀvisible light (UVꢀvis) diffuse reflectance, and thermogravimetric analyses for
the two compounds are also presented, as are dipole moment calculations.
’ INTRODUCTION
JahnꢀTeller (SOJT) distortive cations,25ꢀ28 i.e., octahedrally co-
ordinated d0 transition-metal ions (Ti4þ, V5þ, W6þ, etc.) and lone-
pair cations (Se4þ, Te4þ, I5þ, etc.). With the d0 metal cations, a
distortion from the center of their oxide octahedron toward a corner,
edge, or face is often observed,29 whereas, with the lone-pair cations, a
nonbonded electron pair is found.30ꢀ32 Since the asymmetric
environments are one of the major factors that substantially
influence the materials’ NCS properties, understanding the struc-
tural basis of the local site symmetry is very important. However, the
local asymmetric environment is a necessary, but not sufficient,
condition for creating macroscopic NCS. In other words, the
material may crystallize with the asymmetric units aligned antipar-
allel, leading to macroscopic centrosymmetry. Thus, to understand
the factors that determine overall crystallographic centrosymmetry,
it is important to appreciate and understand the local asymmetry as
well as the macroscopic symmetry. As such, the rational design of
NCS materials remains an ongoing challenge. We have chosen to
investigate the In3þꢀV5þꢀTe4þ (Se4þ)ꢀoxide system. Several
quaternary oxide materials in the MnþꢀV5þꢀTe4þꢀoxide33ꢀ42 or
Both tellurium dioxide (TeO2) and selenium dioxide (SeO2)
have been used widely in the syntheses of a variety of new solid-state
materials, because of their lower melting and triple points (733 ꢀCfor
TeO2, 340 ꢀC for SeO2), respectively. These accessible temperatures
have enabled them to be used as fluxes for crystal growth.1ꢀ4 In
addition, the excellent reactivities of TeO2 and SeO2 have enabled
them to be used in the formation of many new oxide materials.5ꢀ9
The variable coordination environments of the Te4þ and Se4þ
cations have also been of particular interest. Specifically, the Te4þ
cation can exhibit a variety of structural motifs such as a trigonal
pyramid, seesaw, and square pyramid.10ꢀ13 If the various coordina-
tion geometries are combined with other polyhedral moieties, a great
deal of framework architecture flexibility is possible. Finally, the Se4þ
and Te4þ cations inherently possess asymmetric structural geometry
attributable to the nonbonded electron pair. Materials containing
lone-pair cations have been shown to exhibit local noncentrosym-
metric coordination environments.14ꢀ16 Many strategies have been
suggested to increase the incidence of crystallographic noncentro-
symmetry in any new material.17ꢀ20 Noncentrosymmetric (NCS)
materials are of topical and technological interest, because of their
second harmonic generation (SHG), piezoelectric, ferroelectric, and
pyroelectric properties.21ꢀ24 With oxide materials, the NCS struc-
tures are often observed in materials that contain second-order
M
nþꢀV5þꢀSe4þꢀoxide systems have been reported.43ꢀ47 We
were very interested in introducing a p-element (i.e., In3þ) that can
Received: January 20, 2011
Published: April 12, 2011
r
2011 American Chemical Society
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Table 1. Crystallographic Data for InVTe2O8 and InVSe2O8
Table 2. Selected Bond Distances for InVTe2O8 and
InVSe2O8
formula
fw
InVTe2O8
548.96
InVSe2O8
451.68
InVTe2O8
bond distance (Å)
InVSe2O8
bond distance (Å)
space group
a (Å)
b (Å)
c (Å)
P21/n (No. 14)
7.8967(16)
5.1388(10)
16.711(3)
94.22(3)
676.3(2)
4
Pm (No. 6)
4.6348(9)
6.9111(14)
10.507(2)
97.77(3)
333.48(11)
2
bond
bond
In(1)ꢀO(1)
In(1)ꢀO(2)
In(1)ꢀO(3)
In(1)ꢀO(4)
In(1)ꢀO(4)
In(1)ꢀO(5)
V(1)ꢀO(3)
V(1)ꢀO(5)
V(1)ꢀO(7)
V(1)ꢀO(8)
Te(1)ꢀO(1)
Te(1)ꢀO(3)
Te(1)ꢀO(4)
Te(1)ꢀO(6)
Te(2)ꢀO(2)
Te(2)ꢀO(2)
Te(2)ꢀO(6)
Te(2)ꢀO(7)
2.062(9)
2.124(9)
2.197(9)
2.155(9)
2.183(9)
2.178(9)
1.816(9)
1.685(10)
1.830(9)
1.615(9)
1.856(9)
2.131(8)
1.928(9)
2.103(9)
1.874(9)
2.506(9)
1.907(9)
1.905(9)
In(1)ꢀO(1)
In(1)ꢀO(2)
In(1)ꢀO(3)
In(1)ꢀO(4)
In(1)ꢀO(5)
In(1)ꢀO(6)
V(1)ꢀO(7)
2.100(10)
2.198(9)
β (ꢀ)
V (Å3)
Z
2.113(10)
2.199(9)
2.187(10)
2.179(9)
T (ꢀC)
λ (Å)
200.0(2)
0.71073
5.391
200.0(2)
0.71073
4.498
1.936(13)
1.846(6)
F
calcd (g cmꢀ3
)
V(1)ꢀO(8)
μ (mmꢀ1
)
13.254
15.779
V(1)ꢀO(9)
1.587(11)
1.947(13)
1.842(6)
R(F)a
0.0286
0.0343
V(1)ꢀO(10)
V(1)ꢀO(11)
Se(1)ꢀO(1) ꢁ 2
Se(1)ꢀO(5)
Se(2)ꢀO(2)
Se(2)ꢀO(3) ꢁ 2
Se(3)ꢀO(6)
Se(3)ꢀO(7) ꢁ 2
Se(4)ꢀO(4)
Se(4)ꢀO(10) ꢁ 2
2 b
Rw(F o
)
0.0680
2
0.0589
a R(F) = ∑ Fo| ꢀ |Fc /∑|Fo|. b Rw(Fo ) = [∑w(Fo ꢀ Fc2)2/∑w(Fo ) ]
.
2
2 2 1/2
1.691(11)
1.735(15)
1.746(15)
1.677(10)
1.728(15)
1.690(12)
1.738(15)
1.696(11)
form a larger and stable octahedral environment with very interest-
ing structural features. In fact, the longer InꢀO bonds in NCS
In2(Se2O5)3, compared to the GaꢀO and AlꢀO bonds in CS
Al2(Se2O5)3 and Ga2(Se2O5)3, respectively, provided greater flex-
ibility, which, in turn, easily relates the asymmetric moiety in the
structure.3 Here, we report the synthesis, structural determinations,
and complete characterizations of two new quaternary oxide
materials: InVTe2O8 and InVSe2O8. To the best of our knowledge,
the reported materials are the first examples in the In3þꢀV5þꢀ
Te4þ (Se4þ)ꢀoxide family. With the NCS oxide, InVSe2O8, detailed
SHG properties will also be reported.
Korea Basic Science Institute. A hemisphere of data was collected using a
narrow-frame method with scan widths of 0.30ꢀ in omega, and an exposure
time of 5 s/frame. The first 50 frames were remeasured at the end of the data
collection to monitor instrument and crystal stability. The maximum
correction applied to the intensities was <1%. The data were integrated
using the SAINT program,48 with the intensities corrected for Lorentz
factor, polarization, air absorption, and absorption attributable to the
variation in the path length through the detector faceplate. A semiempirical
absorption correction was made on the hemisphere of data with the
SADABS program.49 The data were solved and refined using SHELXS-
97 and SHELXL-97, respectively.50,51 All of the metal atoms were refined
with anisotropic thermal parameters and converged for I > 2σ(I). All
calculations were performed using the WinGX-98 crystallographic software
package.52 Crystallographic data and selected bond distances for the
reported material are given in Tables 1 and 2.
Powder X-ray Diffraction. Powder XRD was used to confirm the
phase purity for the synthesized material. The powder XRD data were
collected on a Scintag XDS2000 diffractometer, at room temperature
(Cu KR radiation, θꢀθ mode, flat-plate geometry), equipped with a
Peltier germanium solid-state detector in the 2θ range of 5ꢀꢀ70ꢀ, with a
step size of 0.02ꢀ and a step time of 1 s. The experimental powder XRD
patterns for both materials are in good agreement with those calculated
data from the single-crystal models.
’ EXPERIMENTAL SECTION
Reagents. In2O3 (Alfa Aesar, 99.9%), V2O5 (Aldrich, 98%), TeO2
(Alfa Aesar, 99.9%), and SeO2 (Aldrich, 98%) were used as received.
Synthesis. Crystals of InVTe2O8 and InVSe2O8 were prepared by
standard solid-state reactions. In2O3 (0.228 g (1.00 ꢁ 10ꢀ3 mol)), V2O5
(0.182 g (1.00 ꢁ 10ꢀ3 mol)), and SeO2 (0.444 g (4.00 ꢁ 10ꢀ3 mol)) or
TeO2 (0.638 g (4.00 ꢁ 10ꢀ3 mol)) was thoroughly mixed with an agate
mortar and pestle, under an atmosphere of dry argon. The respective
reaction mixtures were introduced into fused-silica tubes that were evac-
uated and subsequently sealed. Each tube was gradually heated to 250 ꢀCfor
5 h, and then to 550 ꢀC for 48 h (700 ꢀC for 48 h for InVTe2O8). The
samples were cooled at a rate of 1 ꢀC hꢀ1 to room temperature. The
products contained light brown and light green crystals for InVTe2O8 and
InVSe2O8, respectively. Pure polycrystalline samples of InVTe2O8 and
InVSe2O8 were obtained through similar solid-state reactions. However, the
reaction temperatures have been reduced and several intermittent regrind-
ings have been applied; each reaction mixture within a sealed fused-silica
tube was gradually heated to 250, 350, 400, and 440 ꢀC for 12 h (600 ꢀC for
InVTe2O8) at each temperature with intermediate regrindings. The powder
X-ray diffraction (XRD) patterns on the resultant polycrystalline products
exhibited materials that were single phase and were in good agreement with
the generated patterns from the single-crystal data (see the Supporting
Information).
Infrared Spectroscopy. Infrared spectra were recorded on a
Varian Model 1000 FT-IR spectrometer in the 400ꢀ4000 cmꢀ1 range,
with the sample embedded in a KBr matrix.
UVꢀvis Diffuse Reflectance Spectroscopy. Ultravioletꢀvisible
(UV-vis) reflectance data were collected on a Varian Cary 500 scan
UVꢀvisꢀNIR spectrophotometer over a spectral range of 200ꢀ1500 nm
at room temperature. Poly(tetrafluoroethylene) was used as a reference
material. Reflectance spectra were converted to absorbance data, using the
KubelkaꢀMunk function.53,54
Single-Crystal X-ray Diffraction. The structures of InVTe2O8 and
InVSe2O8 were determined by standard crystallographic methods. A light-
brown plate (0.04 mm ꢁ 0.08 mm ꢁ 0.24 mm) for InVTe2O8 and a light
green plate (0.04 mm ꢁ 0.06 mm ꢁ 0.20 mm) for InVSe2O8 were used for
single-crystal data analyses. All of the data were collected using a Bruker
SMART APEX diffractometer that was equipped with a 1K CCD area
detector, using graphite-monochromated Mo KR radiation at 200 K at the
Thermogravimetric Analysis. Thermogravimetric analysis was
performed on a Setaram LABSYS TG-DTA/DSC thermogravimetric
analyzer. The polycrystalline samples of InVTe2O8 and InVSe2O8 were
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Figure 1. Ball-and-stick representation of InVTe2O8 in the ac-plane. The distorted InO6 octahedra, VO4 tetrahedra, and asymmetric TeO4 polyhedra
link to form a two-dimensional (2D) layered crystal structure (blue, In; cyan, V; green, Te; red, O).
Figure 2. Ball-and-stick diagrams representing (a) InO6 chains along the [010] direction, (b) Te4O12 tetramers, (c) VO4 tetrahedra, and the “linking” of
the polyhedra to form a 2D layer structure of InVTe2O8 in the (d) bc-plane and (e) ac-plane (blue, In; cyan, V; green, Te; red, O).
contained within alumina crucibles and heated at a rate of 10 ꢀC minꢀ1
from room temperature to 800 ꢀC under flowing argon.
Scanning Electron Microscope/Energy-Dispersive Analysis
by X-ray (SEM/EDAX). SEM/EDAX analysis has been performed using
a Hitachi Model S-3400N/Horiba Energy Model EX-250 system. EDAX
for InVTe2O8 and InVSe2O8 reveal In:V:Te and In:V:Se ratios of ∼1:1:2.
Second-Order Nonlinear Optical Measurements. Powder
SHG measurements on polycrystalline InVSe2O8 were performed on a
modified Kurtz-NLO system,55 using 1064-nm radiation. A detailed
description of the equipment and the methodology used has been
published.56 The SHG efficiency has been shown to be strongly
dependent on particle size; therefore, polycrystalline samples were
ground and sieved to distinct particle size ranges (20ꢀ45 μm, 45ꢀ
63 μm, 63ꢀ75 μm, 75ꢀ90 μm, and >90 μm). To make relevant
comparisons with known SHG materials, crystalline R-SiO2 and
LiNbO3 were also ground and sieved into the same particle size
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ranges. Powders with a particle size of 45ꢀ63 μm were used to
compare the SHG intensities. No index matching fluid was used in
any of the experiments.
’ RESULTS AND DISCUSSION
InVTe2O8. InVTe2O8 is a new quaternary In3þꢀV5þꢀTe4þꢀ
oxide material that crystallizes in centrosymmetric space group P21/n
(No. 14). The material exhibits a two-dimensional (2D) layered
crystal structure consisting of InO6 octahedra, VO4 tetrahedra, and
asymmetric TeO4 polyhedra (see Figure 1). Each In3þ cation is
bound to six oxygen atoms in a slightly distorted octahedral
environment, with bond lengths ranging from 2.062(9) Å to
2.197(9) Å. The OꢀInꢀO bond angles range from 72.6(3)ꢀ to
176.7(3)ꢀ. The unique V5þ cation is in a distorted tetrahedral
environment with two “short” VꢀO distances (1.615(9) and
1.685(10) Å) and two “normal” VꢀO distances (1.816(9) and
1.830(9) Å). The OꢀVꢀO bond angles range from 107.3(5)ꢀ to
111.9(4)ꢀ. There are two unique Te4þ cations that are bonded to
four oxygen atoms. The Te(1)4þ cations exhibit two slightly shorter
(1.856(9) and 1.928(9) Å) and two slightly longer TeꢀO (2.103(9)
and 2.131(8) Å) bond distances in a distorted seesaw environment.
However, the Te(2)4þ cations show three shorter bond lengths
(1.874(9) and 1.907(9) Å) and one very long TeꢀO (2.506(9) Å)
bond length. The Te4þ cations are in a highly asymmetric coordina-
tion environment, which is attributable to their lone pairs. The
OꢀTeꢀO bond angles range from 70.0(4)ꢀ to 160.7(3)ꢀ. A list of
the selected bond distances is given in Table 2. The bond distances
are consistent with those previously reported.8,9,44 In connectivity
terms, the structure may be written as a neutral framework of
Figure 3. Ball-and-stick model of InVSe2O8 in the ac-plane (blue, In;
cyan, V; green, Se; red, O). The distorted InO6 octahedra, VO5 square
pyramids, and asymmetric SeO3 polyhedra link to form a three-dimen-
sional (3D) framework structure.
ꢀ
ꢁ
connectivity terms, the structure may be written as a neutral
framework of
0
h
iꢀ1:667
h
iþ0:333
h
iþ0:667
InO2=3O4=3
VO2=2O1=3O1=1
2 TeO2=2O2=3
ꢀ
ꢁ
0
h
iꢀ1:667
h
iꢀ1
h
iþ1:333
Bond valence calculations57,58 on InVTe2O8 result in values of 3.08,
4.96, and 4.02ꢀ4.03 for In3þ, V5þ, and Te4þ, respectively. Zig-zag
chains of InO6 corner-shared octahedra are observed along the [010]
direction (see Figure 2a). The two Te(1)O4 and Te(2)O4 polyhedra
are also corner-shared forming Te2O7 “dimers” (see Figure 2b) that
are linked to form a tetrameric Te4O12 unit (see Figure 2b). Finally,
the InO6 zigzag chains, the Te4O12 tetramers, and the VO4 tetra-
hedra link together and form the novel 2D layered structure
(see Figure 2).
InVSe2O8. InVSe2O8 is another new quaternary mixed metal
oxide material with an In3þꢀV5þꢀSe4þꢀoxide composition
that crystallizes in noncentrosymmetric polar space group Pm
(No. 6). The structure contains distorted InO6 octahedra, VO5
square pyramids, and asymmetric SeO3 polyhedra (see Figure 3).
There is a unique In3þ cation in a distorted octahedral environ-
ment, bound to six oxygen atoms. The InꢀO bond lengths range
from 2.100(10) Å to 2.199(9) Å. The OꢀInꢀO bond angles
range from 74.5(4)ꢀ to 170.6(5)ꢀ. Each V5þ is bound to five
oxygen atoms in a slightly distorted square pyramidal environ-
ment with one “short” (1.587(11) Å) and four “normal” VꢀO
distances (1.842(6)ꢀ1.947(13) Å). The OꢀVꢀO bond angles
range from 85.8(6)ꢀ to 155.7(5)ꢀ. The four unique Se4þ cations
(Se(1)4þꢀSe(4)4þ) are bound to three oxygen atoms. All of the
Se4þ cations are in a highly asymmetric coordination environ-
ment, which is attributed to their nonbonded electron pairs. The
SeꢀO bond distances range from 1.677(10) to 1.746(15) Å. The
OꢀSeꢀO bond angles range from 96.2(5)ꢀ to 108.4(8)ꢀ. A list
of the selected bond distances is given in Table 2. The bond
distances are consistent with those previously reported.3,59,60 In
InO2=3O4=3
VO4=2O1=1
2 SeO2=2O1=3
Bond valence calculations57,58 on InVSe2O8 result in 2.97, 5.09, and
4.06ꢀ4.13 for In3þ, V5þ, and Se4þ, respectively. Similar to In-
VTe2O8, the chains of InO6 octahedra are observed running along
the [010] direction; however, in InVSe2O8, the InO6 octahedra are
edge-shared (see Figure 4a). The VO5 square pyramids are corner-
shared, creating infinite chains running along the [010] direction
(see Figure 4b). Interestingly, all the apical VdO bonds in the VO5
square pyramids are pointing toward the [100] direction within the
chains. The InO6 chains, the VO5 chains, and SeO3 groups are
linked together and form a novel three-dimensional (3D) frame-
work structure (see Figure 4). In InVSe2O8, the SeO3 groups serve
as intrachain and interchain linkers.
Infrared Spectroscopy. InꢀO, VꢀO, TeꢀO, and SeꢀO
vibrations were observed in the infrared spectra. The InꢀO
vibrations are observed at ∼405ꢀ429 cmꢀ1. The bands occurring
at ∼948ꢀ974 and ∼701ꢀ866 cmꢀ1 can be assigned to VdO
(short terminal VꢀO bonds) and VꢀO vibrations, respectively.
The stretches at 547ꢀ788 and 459ꢀ823 cmꢀ1 can be attributed to
TeꢀO and SeꢀO vibrations, respectively. The infrared vibrations
and assignments are listed in Table 3. The assignments are
consistent with those previously reported.3,59,61ꢀ64
UVꢀvis Diffuse Reflectance Spectroscopy. The UVꢀvis
diffuse reflectance spectra for InVTe2O8 and InVSe2O8 have
been deposited in the Supporting Information. InVTe2O8 is light
brown, whereas InVSe2O8 is light green. These spectra show that
the absorption is ∼2.1ꢀ2.8 eV. Absorption (K/S) data were
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Figure 4. Ball-and-stick models representing (a) InO6 chains running along the [010] direction, (b) VO5 chains running along the [010] direction, (c) SeO3
polyhedra, and (d) the “linking” of the polyhedra to form a 3D framework structure of InVSe2O8 in the bc-plane (blue, In; cyan, V; green, Se; red, O).
calculated from the following KubelkaꢀMunk function:53,54
Second-Order Nonlinear Optical Measurements. Since
InVSe2O8 crystallizes in a noncentrosymmetric space group, we
investigated its nonlinear optical properties. Powder SHG measure-
ments, using 1064-nm radiation, indicated that InVSe2O8 has a
SHG efficiency ∼30 times that of R-SiO2. By sieving InVSe2O8
powder into various particle sizes, ranging from 20 μm to 150 μm,
and by measuring the SHG as a function of particle size, we were
able to determine the Type 1 phase-matching capabilities of the
material. As seen in Figure 5, InVSe2O8 is not phase-matchable.
Based on the SHG efficiency and phase-matching measurements,
InVSe2O8 falls into the Class C category of SHG materials, as
defined by Kurtz and Perry.55 Once the SHG efficiency and the
phase-matching capability of a material are known, the bulk SHG
2
ð1 ꢀ RÞ
K
FðRÞ ¼
¼
2R
S
where R is the reflectance, K the absorption, and S the scattering. In
the (K/S)-vs-E plot, extrapolating the linear part of the rising curve
to zero provided the onset of absorption at 2.8 and 2.1 eV for
InVTe2O8 and InVSe2O8, respectively. It is likely that the visible
absorption in the reported compounds can be attributed to charge
transfer in the vanadyl units. The onset of absorption values for the
reported compounds is in good agreement with the previous study
of compounds that contained VO2þ vanadyl units.63,65
Thermogravimetric Analysis. The thermal behaviors of
InVTe2O8 and InVSe2O8 were investigated using thermogravi-
metric analysis (TGA). As indicated by the TGA diagram,
InVTe2O8 is stable up to 800 ꢀC. No weight loss was observed.
However, InVSe2O8 was only stable up to 450 ꢀC. Above this
temperature, decomposition occurs, which is attributable to the
sublimation of SeO2. Powder XRD measurement on the calcined
material under an argon atmosphere revealed that InVSe2O8
decomposes to InVO466 and In2VO5.67 The TGA plots for both
materials are shown in the Supporting Information.
efficiency (Ædeffæexp) can be estimated.68 For InVSe2O8, Ædeffæexp
≈
3.0 pm Vꢀ1
.
StructureꢀProperty Relationships. The SHG response can
be understood by examining the polarization of the asymmetric
polyhedra, since macroscopic NCS is usually observed when
locally polar asymmetric coordination polyhedra add construc-
tively. Thus, determining the “net” direction of the polarizations
enables us to understand the origin and magnitude of the SHG
properties. We assume that the InO6 octahedra do not contribute
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Table 3. Infrared Vibrations (cmꢀ1) for InVTe2O8 and
InVSe2O8
InVTe2O8
InꢀO
VdO
VꢀO
TeꢀO
405
948
510
863
547
701
788
InVSe2O8
InꢀO
VdO
VꢀO
SeꢀO
429
974
510
866
459
665
795
823
Figure 6. Ball-and-stick representation of InVSe2O8 (blue, In; cyan, V;
green, Se; red, O). A moment is observed toward the [100] direction,
which is attributable to the alignment of the VO5 square pyramids. Also,
a larger net moment attributed to the sum of the asymmetric environ-
ment, which is attributable to the alignment of lone pairs on Se4þ
cations, is observed in the [100] direction. Once taken as a whole, a net
moment is observed along the [100] direction.
attributable to the lack of greater constructive addition of the
dipole moments. We believe that the SHG light (532 nm) may
also be underestimated, which is attributable to the light green
color of InVSe2O8.
In order to better understand the asymmetric coordination
environment, we also calculated the local dipole moment for
Te4þ and Se4þ in InVTe2O8 and InVSe2O8. This approach has
been described earlier, with respect to metal oxyfluoride
octahedra.69,70 We found that the local dipole moments for the
two unique TeO4 polyhedra—Te(1)O4 and Te(2)O4—in In-
VTe2O8 are ∼9.08 D and ∼6.87 D, respectively. [Here, D
represents Debyes.] Also, the local dipole moments for the four
SeO3 polyhedra in InVSe2O8 exhibit very similar values that
range from 7.09 D to 7.87 D. The dipole moments for Se(1)O3,
Se(2)O3, Se(3)O3, and Se(4)O3 were calculated to be 7.43, 7.09,
7.87, and 7.50 D, respectively. The values are consistent with
those recently reported dipole moments for TeO4 and SeO3
polyhedra.60,71 The local dipole moment for the VO5 group can
be calculated to be 28.19 D, using the same calculation method.
Figure 5. Phase-matching curve (Type 1) for InVSe2O8. The curve is
drawn to guide the eye, and is not a fit to the data.
significantly toward the SHG efficiency, since the In3þ is not a
SOJT distortive cation. For the V5þ cations, each VO5 square
pyramid unit is aligned toward one direction. More specifically,
all the apical VdO bonds for the VO5 square pyramids are
directed toward the [100] direction (see Figure 6); since the local
moment for the VO5 square pyramids is in the opposite direction
of the VdO bond, a net moment is observed pointing in the
[100] direction. Each SeO3 unit also has a dipole moment that is
attributable to the different charge distribution on Se and O
atoms, as well as the asymmetric environment arising from the
alignment of lone pairs. The lone pairs on the asymmetric cations
Se(1)4þ and Se(2)4þ approximately point toward the [001] and
[001] directions, respectively; thus, the polarizations associated
with Se(1)4þ and Se(2)4þ cancel. The lone pairs attached on
Se(3)4þ and Se(4)4þ point approximately parallel toward the
[100] direction (see Figure 6). The local moment for the SeO3
points in the opposite direction of the lone pair. Thus, the net
effect of this alignment of lone pairs on Se4þ cations is a larger
moment in the [100] direction. One can also notice that the
moments for VO5 square pyramids and SeO3 are pointed in
opposite directions. Taking the moments as a whole, a net
moment is observed along the [100] direction. As we will discuss
later, the local dipole moment calculations indicate that the
moment for VO5 square pyramid is larger than that of the SeO3
group. Our SHG measurements show the relatively weak SHG
efficiency (∼30 times that of R-SiO2), which we suggest is
’ CONCLUSIONS
We have successfully synthesized two new quaternary mixed
metal oxide materials—InVTe2O8 and InVSe2O8—by standard
solid-state reactions. Although the materials are stoichiometrically
equivalent, crystallographic data indicate that InVTe2O8 is centro-
symmetric with a two-dimensional (2D) layered structure, whereas
InVSe2O8 is noncentrosymmetric (NCS) with a three-dimensional
(3D) framework structure. Powder second-harmonic generation
(SHG) measurements on InVSe2O8, using 1064-nm radiation,
indicate that the material is not phase-matchable (Type 1), with a
SHG efficiency ∼30 times that of R-SiO2. Full spectroscopic
characterizations, thermal analysis, and dipole moment have been
performed on the reported materials. The combination of cations
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ARTICLE
with greater flexibility and asymmetric polyhedra may be the driving
force for the crystallization of a NCS structure. We are in the process
of synthesizing other quaternary mixed metal oxide materials and
will be reporting on them shortly.
(19) Hwu, S.-J.; Ulutagay-Kartin, M.; Clayhold, J. A.; Mackay, R.;
Wardojo, T. A.; O’Connor, C. J.; Kraweic, M. J. Am. Chem. Soc. 2002, 124,
12404.
(20) Welk, M. E.; Norquist, A. J.; Arnold, F. P.; Stern, C. L.;
Poeppelmeier, K. R. Inorg. Chem. 2002, 41, 5119.
(21) Jona, F.; Shirane, G. Ferroelectric Crystals; Pergamon Press:
Oxford, U.K., 1962.
(22) Cady, W. G. Piezoelectricity: An Introduction to the Theory and
Applications of Electromechanical Phenomena in Crystals; Dover: New
York, 1964.
(23) Lang, S. B. Sourcebook of Pyroelectricity; Gordon & Breach
Science: London, 1974.
(24) Galy, J.; Meunier, G. J. Solid State Chem. 1975, 13, 142.
(25) Opik, U.; Pryce, M. H. L. Proc. R. Soc. London A 1957,
A238, 425.
’ ASSOCIATED CONTENT
S
Supporting Information. X-ray crystallographic file in
b
CIF format, calculated and observed X-ray diffraction patterns,
thermogravimetric analysis diagrams, UVꢀvis diffuse reflectance
spectra, Infrared spectra, and ORTEP drawings for InVTe2O8
and InVSe2O8. This material is available free of charge via the
Internet at http://pubs.acs.org.
(26) Bader, R. F. W. Mol. Phys. 1960, 3, 137.
(27) Pearson, R. G. J. Mol. Struct.: THEOCHEM 1983, 103, 25.
(28) Wheeler, R. A.; Whangbo, M.-H.; Hughbanks, T.; Hoffmann,
R.; Burdett, J. K.; Albright, T. A. J. Am. Chem. Soc. 1986, 108, 2222.
(29) Goodenough, J. B. Annu. Rev. Mater. Sci. 1998, 28, 1.
(30) Orgel, L. E. J. Chem. Soc. 1959, 3815.
’ AUTHOR INFORMATION
Corresponding Author
*Tel.: þ82-2-820-5197. Fax: þ82-2-825-4736. E-mail: kmok@
cau.ac.kr.
(31) Waghmare, U. V.; Spaldin, N. A.; Kandpal, H. C.; Seshadri, R.
Phys. Rev. B 2003, 67, 125111.
(32) Stoltzfus, M. W.; Woodward, P.; Seshadri, R.; Park, J.-H.;
Bursten, B. Inorg. Chem. 2007, 46, 3839.
’ ACKNOWLEDGMENT
(33) Darriet, J.; Guillaume, G.; Wilhelmi, K. A.; Galy, J. Acta Chem.
Scand. 1972, 26, 59.
(34) Hong, Y. S.; Darriet, J.; Yoon, J. B.; Choy, J. H. Jpn. J. Appl. Phys.,
Part 1 1999, 38, 1506.
(35) Harrison, W. T. A.; Buttery, J. H. N. Z. Anorg. Allg. Chem. 2000,
This research was supported by Basic Science Research
Program through the National Research Foundation of Korea
(NRF) funded by Ministry of Education, Science & Technology
(throguh Grant No. 2010-0002480). P.S.H. thanks the Robert A.
Welch Foundation (through Grant No. E-1457), the Texas
Center for Superconductivity, and the NSF (No. DMR-
0652150) for support.
626, 867.
(36) Rozier, P.; Vendier, L.; Galy, J. Acta Crystallogr., Sect. C: Cryst.
Struct. Commun. 2002, C58, i111.
(37) Hou, J. Y.; Huang, C. C.; Zhang, H. H.; Yang, Q. Y.; Chen, Y. P.;
Xu, J. F. Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 2005, C61, i59.
(38) Johnston, M. G.; Harrison, W. T. A. Acta Crystallogr., Sect. C:
Cryst. Struct. Commun. 2007, C63, i57.
(39) Pitzschke, D.; Jansen, M. Z. Anorg. Allg. Chem. 2007, 633, 1563.
(40) Jiang, H.; Huang, S.; Fan, Y.; Mao, J.; Cheng, W. Chem.—Eur. J.
2008, 14, 1972.
(41) Grzechnik, A.; Halasyamani, P. S.; Chang, H.; Friese, K. J. Solid
State Chem. 2009, 182, 1570.
(42) Zhang, D.; Johnsson, M. Acta Crystallogr., Sect. C: Cryst. Struct.
Commun. 2009, C65, i9.
(43) Kim, Y. T.; Kim, Y. H.; Park, K.; Kwon, Y. U.; Young, V. G., Jr.
J. Solid State Chem. 2001, 161, 23.
’ REFERENCES
(1) Champarnaud-Mesjard, J. C.; Frit, B.; Chagraoui, A.; Tairi, A.
J. Solid State Chem. 1996, 127, 248.
(2) Champarnaud-Mesjard, J. C.; Frit, B.; Chagraoui, A.; Tairi, A. Z.
Anorg. Allg. Chem. 1996, 622, 1907.
(3) Ok, K. M.; Halasyamani, P. S. Chem. Mater. 2002, 14, 2360.
(4) Zhang, W.; Tao, X.; Zhang, C.; Gao, Z.; Zhang, Y.; Yu, W.;
Cheng, X.; Liu, X.; Jiang, M. Cryst. Growth Des. 2008, 8, 307.
(5) Galy, J.; Lindqvist, O. J. Solid State Chem. 1979, 27, 279.
(6) Alonso, J. A.; Castro, A.; Puebla, E. G.; Monge, M. A.; Rasines, I.;
Valero, C. R. J. Solid State Chem. 1987, 69, 36.
(7) Halasyamani, P. S.; O’Hare, D. Chem. Mater. 1998, 10, 646.
(8) Blanchandin, S.; Champarnaud-Mesjard, J. C.; Thomas, P.; Frit,
B. J. Alloys Compd. 2000, 306, 175.
(44) Sivakumar, T.; Chang, H. Y.; Baek, J.; Halasyamani, P. S. Chem.
Mater. 2007, 19, 4710.
(45) Jiang, H.; Kong, F.; Fan, Y.; Mao, J. Inorg. Chem. 2008, 47, 7430.
(46) Li, P.-X.; Zhang, S.-Y.; Mao, J.-G. Dalton Trans. 2010, 39,
11560.
(9) Ok, K. M.; Zhang, L.; Halasyamani, P. S. J. Solid State Chem.
2003, 175, 264.
(10) Alcock, N. W.; Harrison, W. D. Acta Crystallogr., Sect. B: Struct.
Crystallogr. Cryst. Chem. 1982, B38, 1809.
(47) Zhang, S.-Y.; Hu, C.-L.; Sun, C.-F.; Mao, J.-G. Inorg. Chem.
2010, 49, 11627.
(48) SAINT, Version 4.05; Program for Area Detector Absorption
Correction, Siemens Analytical X-ray Instruments, Madison, WI, 1995.
(49) Blessing, R. H. Acta Crystallogr., Sect. A: Found. Crystallogr.
1995, A51, 33.
(11) Mayer, H.; Weil, M. Z. Anorg. Allg. Chem. 2003, 629, 1068.
(12) Ok, K. M.; Orzechowski, J.; Halasyamani, P. S. Inorg. Chem.
2004, 43, 964.
(13) Kim, M. K.; Kim, S.-H.; Chang, H.-Y.; Halasyamani, P. S.; Ok,
(50) Sheldrick, G. M. SHELXS-97—A Program for Automatic Solu-
tion of Crystal Structures; University of Goettingen: Goettingen, Ger-
many, 1997.
K. M. Inorg. Chem. 2010, 49, 7028.
(14) Halasyamani, P. S.; Poeppelmeier, K. R. Chem. Mater. 1998, 10,
2753.
(51) Sheldrick, G. M. SHELXL-97—A Program for Crystal Structure
Refinement; University of Goettingen: Goettingen, Germany, 1997.
(52) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.
(53) Kubelka, P.; Munk, F. Z. Tech. Phys. 1931, 12, 593.
(54) Tauc, J. Mater. Res. Bull. 1970, 5, 721.
(55) Kurtz, S. K.; Perry, T. T. J. Appl. Phys. 1968, 39, 3798.
(56) Ok, K. M.; Chi, E. O.; Halasyamani, P. S. Chem. Soc. Rev. 2006, 35,
710.
(15) Ok, K. M.; Bhuvanesh, N. S. P.; Halasyamani, P. S. Inorg. Chem.
2001, 40, 1978.
(16) Ok, K. M.; Halasyamani, P. S. Angew. Chem., Int. Ed. 2004, 43,
5489.
(17) Kepert, C. J.; Prior, T. J.; Rosseinsky, M. J. J. Am. Chem. Soc.
2000, 122, 5158.
(18) Maggard, P. A.; Stern, C. L.; Poeppelmeier, K. R. J. Am. Chem.
Soc. 2001, 123, 7742.
4479
dx.doi.org/10.1021/ic200135k |Inorg. Chem. 2011, 50, 4473–4480

Inorganic Chemistry
ARTICLE
(57) Brown, I. D.; Altermatt, D. Acta Crystallogr., Sect. B: Struct. Sci.
1985, B41, 244.
(58) Brese, N. E.; O’Keeffe, M. Acta Crystallogr., Sect. B: Struct. Sci.
1991, B47, 192.
(59) Sivakumar, T.; Ok, K. M.; Halasyamani, P. S. Inorg. Chem. 2006, 45,
3602.
(60) Lee, D. W.; Ok, K. M. Solid State Sci. 2010, 12, 2036.
(61) Vaughey, J. T.; Harrison, W. T. A.; Dussack, L. L.; Jacobson,
A. J. Inorg. Chem. 1994, 33, 4370.
(62) Frost, R. L.; Erickson, K.; Weier, M. L. Spectrochem. Acta 2004,
60A, 2419.
(63) Sullens, T. A.; Albrecht-Schmitt, T. E. Inorg. Chem. 2005, 44,
2282.
(64) Zheng, S.-T.; Zhang, J.; Yang, G.-Y. Inorg. Chem. 2005, 44,
2426.
(65) Sykora, R. E.; Ok, K. M.; Halasyamani, P. S.; Wells, D. M.;
Albrecht-Schmitt, T. E. Chem. Mater. 2002, 14, 2741.
(66) Touboul, M.; Toledano, P. Acta Crystallogr., Sect. B: Struct.
Crystallogr. Cryst. Chem. 1980, B36, 240.
(67) Senegas, J.; Manaud, J. P.; Galy, J. Acta Crystallogr., Sect. B:
Struct. Crystallogr. Cryst. Chem. 1975, B31, 1614.
(68) Goodey, J.; Broussard, J.; Halasyamani, P. S. Chem. Mater.
2002, 14, 3174.
(69) Maggard, P. A.; Nault, T. S.; Stern, C. L.; Poeppelmeier, K. R.
J. Solid State Chem. 2003, 175, 25.
(70) Izumi, H. K.; Kirsch, J. E.; Stern, C. L.; Poeppelmeier, K. R.
Inorg. Chem. 2005, 44, 884.
(71) Kim, M. K.; Jo, V.; Lee, D. W.; Ok, K. M. Dalton Trans. 2010, 39,
6037.
4480
dx.doi.org/10.1021/ic200135k |Inorg. Chem. 2011, 50, 4473–4480