B-site deficiencies in A-site-ordered perovskite LaCu3Pt 3.75O12

Article abstract of DOI:10.1021/ic302809v

An A-site-ordered perovskite LaCu₃Pt_3.75O ₁₂ was synthesized by replacing Ca²⁺ with La³⁺ in a cubic quadruple AA′₃B₄O₁₂-type perovskite CaCu₃Pt₄O₁₂ under high-pressure and high-temperature of 15 GPa and 1100 C. In LaCu₃Pt _3.75O₁₂, 1/16 of B-site cations are vacant to achieve charge balance. The B-site deficiencies were evidenced by crystal structure refinement using synchrotron X-ray powder diffraction, hard X-ray photoemission spectroscopy, and soft X-ray absorption spectroscopy, leading to the ionic model La³⁺Cu²⁺₃Pt⁴⁺_3.75O ^2-₁₂. Magnetic susceptibility data for this compound indicated a spin-glass-like behavior below T_g = 3.7 K, which is attributed to disturbance of the antiferromagnetic superexchange interaction by the B-site deficiencies.

Full text of DOI:10.1021/ic302809v

Article
pubs.acs.org/IC
B‑Site Deficiencies in A‑site-Ordered Perovskite LaCu Pt O
3
3.75 12
†
,†,‡,§
∥
⊥
⊗,○
Mikiko Ochi, Ikuya Yamada,*
Kenya Ohgushi, Yoshihiro Kusano, Masaichiro Mizumaki,
†
‡
#,§,Δ
#
#
Ryoji Takahashi, Shunsuke Yagi, Norimasa Nishiyama,
Toru Inoue, and Tetsuo Irifune
†Department of Chemistry, Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime
90-8577, Japan
7
‡
Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570,
Japan
§
Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Chiyoda-ku,
Tokyo 102-0075, Japan
∥
Institute for Solid State Physics (ISSP), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 227-8581, Japan
⊥
Department of Applied Arts and Design, Kurashiki University of Science and the Arts, Kurashiki, Okayama 712-8505, Japan
⊗
Japan Synchrotron Radiation Research Institute (JASRI), Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
○
Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 5 Sanbancho,
Chiyoda-ku, Tokyo 102-0075, Japan
#
Geodynamics Research Center (GRC), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
S Supporting Information
*
ABSTRACT: An A-site-ordered perovskite LaCu Pt3.75O12
3
was synthesized by replacing Ca2+ with La in a cubic
3+
quadruple AA′ B O -type perovskite CaCu Pt O under
3
4
12
3
4
12
high-pressure and high-temperature of 15 GPa and 1100 °C.
In LaCu Pt O , 1/16 of B-site cations are vacant to achieve
3
3.75 12
charge balance. The B-site deficiencies were evidenced by
crystal structure refinement using synchrotron X-ray powder
diffraction, hard X-ray photoemission spectroscopy, and soft
X-ray absorption spectroscopy, leading to the ionic model
3+
2+
4+
2−
La Cu 3Pt 3.75O . Magnetic susceptibility data for this compound indicated a spin-glass-like behavior below T = 3.7 K,
12
g
which is attributed to disturbance of the antiferromagnetic superexchange interaction by the B-site deficiencies.
INTRODUCTION
AA′ B O -type perovskites can tolerate various types of
2+ 4+ 5+ 2−
3
4
12
■
cation deficiencies. For example, □ Cu Ti Ta
O
has a
12
1
3
2
2
Perovskite oxides ABO have been investigated extensively
3
2+
5+
2−
full vacancy at A-sites, and □ (□ Cu 2)Ta 4O contains
1
1
12
because of their fascinating electronic properties. Cation
substitutions of A/B-sites drastically change the structure and
electronic properties of perovskite oxides, leading to intriguing
phenomena such as metal−insulator transitions, colossal
full- and 1/3-vacancies at A- and A′-sites, respectively, where □
9
3+
2+
4+
2−
represents a vacancy. Ln
□
Cu Ti
O
(or
12
2
/3 1/3
3
4
Ln Cu Ti O , Ln: trivalent lanthanide metal ion) contains
2/3
3
4
12
9
1
deficiencies at one-third of A-site. In all of these compounds,
cation deficiencies are introduced to achieve electrical neutral-
ity. The effects of A-site deficiencies on the magnetic properties
for Ln Cu Ti O perovskites have been compared with those
magnetoresistance, and superconductivity. Large differences
in ionic size, valence, and coordination preference between the
substituting and substituted ions induce perovskite-type
structures with cation ordering. CaCu Ti O is a typical
2/3
3
4
12
3
4
12
10
of the parent compound CaCu Ti O . CaCu Ti O is an
3
4
12
3
4
12
example of a quadruple A-site-ordered perovskite, AA′ B O ,
3
4
12
2
,3
antiferromagnetic insulator with a Nee
K, in which long-range ordering of the localized Cu spins (S =
/2) are dominated by antiferromagnetic superexchange
interaction via the Cu−O−Ti−O−Cu pathway, although
́
l temperature (T ) of 25
N
with a unit cell of 2a × 2a × 2a (Figure 1a), where a
p
p
p
p
2+
represents the unit cell edge of a simple ABO perovskite. In
3
1
this structure, A-sites of a simple perovskite are segregated into
A- and A′-sites with 1:3-type ordering. Three quarters of A-sites
1
1
weak direct ferromagnetic interaction works in Cu−Cu.
(
=A′-sites) are surrounded by four nearest-neighbor oxygen
Because A-site ions are not involved in the magnetic interaction
of A′-site Cu spins and the magnetic moments of Ln 4f
electrons are decoupled to Cu 3d spins, the magnetic properties
ions to form pseudosquare A′O planes. The other quarter of
4
A-sites are coordinated by 12 oxygen ions, forming AO12
icosahedra. Extensive research on this system has found a
wide variety of interesting phenomena such as high dielectric
4
5,6
constant, low-field magnetoresistance,
heavy-fermion-like
Received: December 21, 2012
Published: March 21, 2013
7
8
behavior, and giant negative thermal expansion.
©
2013 American Chemical Society
3985
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Inorganic Chemistry
Article
spectroscopy (XAS) revealed that the obtained sample contains
cation deficiencies at B-sites, and can be represented as a
nominal chemical formula of LaCu Pt3.75O12 (LCPO). This is
3
the first example of B-site deficiencies in AA′ B O -type
3
4
12
perovskites. The deficiencies at the Pt sites realize charge
3+
2+
4+
2−
balance to form the ionic state of La Cu 3Pt 3.75O 12.
Magnetic susceptibility measurements indicate a spin-glass-like
behavior below T = 3.7 K, in contrast to the long-range
g
antiferromagnetic ordering for CCPO below 40 K.
EXPERIMENTAL SECTION
■
A polycrystalline LCPO sample was synthesized from a mixture of
La O , CuO, Cu O, and PtO , all 99.9% and purchased from Rare
2
3
2
2
Metallic, Japan, in a molar ratio of 1:4:1:8. The La O powder was
2
3
calcined at 1000 °C for 24 h before use. The starting mixture was
added to a gold capsule with an inner diameter of 2.8 mm and a height
of 5.0 mm in a nitrogen-filled glovebox. The gold capsule was placed
into an octahedral (Mg,Co)O pressure transmitting medium with a
graphite furnace. The (Mg,Co)O medium was surrounded by eight
WC anvils with truncation and compressed to 15 GPa using a Kawai-
type high-pressure apparatus at GRC, Ehime University. The sample
was heated up to 1100 °C in 20 min, kept at this temperature for 5
min, and then the pressure was released. A reference polycrystalline
CCPO sample was prepared using the procedure described in the
1
2
literature. SXRD data were acquired using a Debye−Scherrer camera
at the BL02B2 beamline of SPring-8. The wavelength was determined
to be 0.51852 Å using a CeO standard. The SXRD data was refined
2
1
3
using the Rietveld program RIETAN-FP. ED patterns were collected
at room temperature using a transmission electron microscope (TEM,
TOPCON EM-002B) with an accelerating voltage of 200 kV. XPS
measurements were conducted with a spectrometer (VG-SCIENTA R-
4
000) installed at the BL47XU beamline of SPring-8. The incident
photon energy was 7.94 keV. The XPS data of the inner-shell electrons
of Pt 4d were collected at 300 K. The energy scale was calibrated using
the Fermi edge of a gold-deposited sample. The energy resolution of
this system was about 280 meV around 7.94 keV. XAS measurements
were performed using the total electron yield method at the BL27SU
beamline of SPring-8. The Cu L -edge XAS spectra were collected at
Figure 1. (a) Crystal structure of an AA′ B O -type perovskite. Large
3
4
12
2,3
green spheres, medium blue spheres with planar coordination, and
small red spheres represent A, A′, and O atoms, respectively.
Octahedra represent BO6 polyhedral units. (b) Observed SXRD
3
00 K. The energy resolution, ΔE/E, was greater than 5000. Magnetic
susceptibility data were collected between 5 and 300 K in an external
field of 1000 Oe, and between 2 and 5 K in an external field of 50 Oe,
in zero-field-cooling (ZFC) and field-cooling (FC) modes using a
SQUID magnetometer (Quantum Design, MPMS-XL).
pattern and the Rietveld refinement result for LaCu Pt O . Dotted
3
3.75 12
and solid lines are observed and calculated patterns, respectively. The
difference between the observed and the calculated patterns is shown
at the bottom. The vertical marks indicate the Bragg peak positions of
RESULTS AND DISCUSSION
■
LaCu Pt3.75O12 (upper) and platinum metal (lower). (c) ED patterns
3
SXRD data and the results of the Rietveld refinement of LCPO
are presented in Figure 1b. The primary phase was identified as
a cubic AA′ B O -type perovskite with a lattice constant a of
for LaCu Pt3.75O12 along the [11
K.
̅
̅
̅
3
3
4
12
∼
7.54 Å. The sample contained metallic platinum (13.5 wt %)
of Cu ions are unchanged in Ln Cu Ti O perovskites,
and unknown phase(s) (estimated to be a few wt % at most) as
impurities. ED patterns of LCPO along the [110], [111], and
[210] zone axes are shown in Figure 1c. These ED patterns
could be indexed with a space group Im3 (No. 204). The initial
2
/3
3
4
12
resulting in almost the same Nee
́
l temperatures (T ∼ 25 K) as
̅
̅
N
1
0
CaCu Ti O . Hence, A-site deficiencies hardly affect the
̅
3
4
12
magnetic properties of A′-site Cu spins.
̅
Recently, we reported a platinum-based AA′ B O -type
crystal structure refinement for LCPO was performed using a
stoichiometric model LaCu Pt O , which is isostructural with
CCPO. The structure model for the final refinement was
considered based on the spectroscopic data, as discussed later.
The valence states of Pt and Cu ions in CCPO and LCPO
were investigated using XPS and XAS. Figure 2a shows Pt 4d
XPS data of CCPO and LCPO. The binding energy of Pt 4d
3
4
12
12
perovskite CaCu Pt O (CCPO). Long-range antiferromag-
3
4
12
3
4
12
12
netic ordering of the Cu spins in CCPO (TN = 40 K) is
dominated by superexchange interaction through the Cu−O−
1
1
Pt−O−Cu pathway in the same manner as CaCu Ti O ,
3
4
12
where Pt4 ions in a low spin configuration (5d , t e ) are
+
6
6
0
2g
g
considered to play a role in the superexchange interaction like
5
/2
the Ti4 ions (3d , t e ) of CaCu Ti O . In this paper, we
+
0
0
0
of CCPO is about 317.6 eV, which is close to that of Pt O
2
14
4+
2
g
g
3
4
12
2
+
3+
report replacement of Ca by La in CCPO using high-
pressure and high-temperature of 15 GPa and 1100 °C. Crystal
structure refinement based on electron diffraction (ED),
synchrotron X-ray powder diffraction (SXRD), hard X-ray
photoemission spectroscopy (XPS), and soft X-ray absorption
(∼318 eV). XAS spectra of the Cu L -edges of CCPO and
2,3
LCPO are depicted in Figure 2b. The spectral shapes and peak
positions (930.3 and 950.6 eV for L - and L -edges,
respectively) of CCPO are similar to those of
Ca Cu 3Ti 4O
3
2
2+
2+
4+
2−
15
(∼930 and ∼950 eV). The above XPS
12
3
986
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Inorganic Chemistry
Article
16
confirmed in a simple perovskite, 1/16 (= 6.25%) in LCPO
may be tolerated. Therefore, we conclude that the LCPO phase
obtained in this study is LaCu Pt O . The absence of
3
3.75 12
superlattice reflections in the ED patterns suggests that the
deficiencies at Pt sites are randomly distributed. The structure
parameters and selected metal−oxygen bond lengths of LCPO
1
7,18
are listed in Table 1. The bond valence sums (BVS)
for La,
Cu, and Pt were 3.15, 2.05, and 3.99, respectively, which are
consistent with the above-mentioned ionic model.
Table 1. Refined Structure Parameters, Selected Bond
a
Lengths, and BVS for LaCu Pt3.75O12
3
g (Pt)
0.933(4)
0.3099(10)
0.1704(11)
0.57(5)
0.65(5)
0.477(13)
1.47(18)
2.667(9)
1.925(7)
2.869(9)
2.030(3)
3.15
x (O)
y (O)
B (La)/Å2
B (Cu)/Å2
B (Pt)/Å2
B (O)/Å2
La−O (×12)/Å
Cu−O (×4)/Å
Cu−O (×4)/Å
Pt−O (×6)/Å
BVS (La)
BVS (Cu)
BVS (Pt)
Figure 2. (a) Pt 4d XPS spectra of LaCu Pt3.75O12 and CaCu Pt O at
3
3
4
12
2.05
room temperature. (b) XAS of Cu L-edges of LaCu Pt3.75O12 and
3
3.99
CaCu Pt O at room temperature.
3
4
12
a
̅
Space group: Im3 (No.204); atomic sites: La 2a (0, 0, 0), Cu 6b (0,
1
1
1
1
1
/2
, / ), Pt 8c ( / , / , / ), O 24g (x, y, 0); lattice constant a =
2 4 4 4
and XAS data confirm that the valence states of Pt and Cu ions
7
.54045(10) Å, Rwp = 7.377%, R = 2.901%, and GOF = 1.2430. The
B
are +4 and +2, respectively, and agree with the ionic model
site occupancy factors g for La, Cu, and O were fixed at unity.
2
+
2+
4+
2−
Ca Cu 3Pt 4O
as suggested by the structure refinement
12
12
in our previous report. The binding energy of Pt 4d5/2 XPS
and peak positions of Cu L -edge XAS data of LCPO are close
The physical properties of LCPO were investigated to
2
,3
to those of CCPO (Figure 2a and b, respectively). Therefore,
the valence states of Pt and Cu ions in LCPO are identical to
those in CCPO, and the valences of these two ions are not
elucidate the effect of B-site deficiencies. Both LCPO and
6
CCPO exhibited high resistivity (>∼10 Ω cm at room
temperature), which disturbed electrical resistivity measure-
ment and indicated their insulating nature. These compounds
are expected to be band insulators with no effective conduction
3
+
2+
changed by substitution of La for Ca . The above
spectroscopic analyses clearly exclude the stoichiometry of
3.75+
6
the LCPO sample because reduced ions of either Pt
Cu
or
should be generated to maintain the charge balance of
the stoichiometric composition of LaCu Pt O .
carriers, as expected from the low spin configuration (5d ,
1.67+
6
0
4+
t e ) of the Pt ions in the octahedral coordination of B-
2g g
sites. The magnetic properties of LCPO differed drastically
from the antiferromagnetic behavior of CCPO. Figure 3a shows
the temperature dependence of the magnetic susceptibility of
LCPO between 5 and 300 K in the ZFC mode. The FC data
(not shown) were almost identical to those in the ZFC mode in
this temperature range. The inverse magnetic susceptibility
follows the Curie−Weiss law down to 15 K (Figure 3b). Note
that the antiferromagnetic transition disappears in LCPO.
LCPO exhibits spin-glass-like behavior below 3.7 K (the inset
of Figure 3a), as evidenced by a deviation between FC and ZFC
3
4
12
We considered possible structure models for LCPO to
explain its spectroscopic data. Cation deficiencies at La, Cu, or
2
+
4+
Pt sites can rationally explain the Cu and Pt valence states,
3
+
2+
4+
2−
with corresponding structure models La
La Cu 2.5Pt 4O , and La Cu 3Pt 3.75O 12, respectively.
Cu 3Pt 4O 12,
/3
2−
2
3+
2+
4+
2−
3+
2+
4+
12
To reveal the most plausible model, we refined the occupancy
factor g for each site using these models. The g values obtained
from the refinement were 1.101(6), 1.077(7), and 0.933(4) for
La, Cu, and Pt sites, respectively. In the case of the former two
models, the g values are meaningless because they are larger
than unity, implying there are no deficiencies at La and Cu
sites. In contrast, refinement of the latter model with
deficiencies at Pt sites gave a plausible g value. The nominal
chemical formula calculated from the final refinement result for
−1
modes. The inverse magnetic susceptibility, χ (T) (= H/M),
of LCPO in the temperature range 100−300 K were fitted
−1
using the Curie−Weiss formula: χ (T) = (T − θ)/C, where C
and θ are the Curie constant and Weiss temperature,
respectively. Curie−Weiss fitting gave C = 1.188(5) emu K/
mol and θ = −33.2(2) K. The effective paramagnetic moment
this model was LaCu Pt
O , which is identical to that of
3.732(16) 12
3
the B-site deficiency model LaCu Pt O within the analytical
of LCPO is calculated to be 1.78 μ per Cu, which is consistent
3
3.75 12
B
2+
error. The reliability factors of the final refinement (Rwp
=
with the theoretical value of 1.75 μ for Cu ions (S = 1/2).
B
7
.377%, R = 2.901%, and goodness-of-fit, GOF = 1.2430) were
The above experimental results demonstrate that the LCPO
sample prepared under high-pressure and high-temperature of
15 GPa and 1100 °C contains a number of cation deficiencies
at B-sites and that the valence states of the Cu2+ and Pt ions
are retained. The magnetic properties changed from the long-
B
improved from those based on the stoichiometric composition
model (Rwp = 7.754%, R = 3.036%, and GOF = 1.3063). The
B-site deficiencies are uncommon in perovskite-type com-
pounds. However, since ∼8% B-site deficiencies were
B
4+
3
987
dx.doi.org/10.1021/ic302809v | Inorg. Chem. 2013, 52, 3985−3989

Inorganic Chemistry
Article
pathway. Thus, the magnetic interactions in LCPO should
provide magnetically disordered states, resulting in the short-
range spin-glass-like magnetic ordering. This is in contrast to
the small influence that A-site deficiencies have on the magnetic
10
properties of Ln Cu Ti O perovskites, confirming that the
2/3
3
4
12
Pt ions at B-sites contribute substantially to the magnetic
properties of LCPO.
In conclusion, we synthesized the A-site-ordered perovskite
LaCu Pt O under high pressure and high temperature of 15
3
3.75 12
GPa and 1100 °C. B-site deficiencies with a proportion of 1/16
were evidenced by the Rietveld refinement of a structure model
derived from electron diffraction, X-ray photoemission, and X-
ray absorption spectroscopy. The spin-glass-like magnetic
properties of LCPO are explained by random disturbance of
the antiferromagnetic superexchange interaction caused by the
B-site cation deficiencies.
ASSOCIATED CONTENT
■
*
S
Supporting Information
Crystallographic data for LaCu Pt O (CIF). This material is
3
3.75 12
available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
■
Corresponding Author
*
E-mail: i-yamada@21c.osakafu-u.ac.jp. Phone: +81-72-254-
9817.
Figure 3. (a) Temperature dependence of the magnetic susceptibility
in ZFC mode for LaCu Pt3.75O12 and CaCu Pt O (data from ref 12)
3
3
4
12
Present Address
Deutsches Elektronen Synchrotron (DESY), 22607 Hamburg,
Germany.
in an external field of 1000 Oe between 5 and 300 K. The inset shows
the temperature dependence of the magnetic susceptibility in ZFC and
FC modes in an external field of 50 Oe between 2 and 5 K. (b) Inverse
Δ
magnetic susceptibility in ZFC mode for LaCu Pt3.75O12 in an external
field of 1000 Oe between 5 and 300 K.
Notes
3
The authors declare no competing financial interest.
range antiferromagnetic ordering of Cu spins for CCPO to
short-range spin-glass-like ordering for LCPO. Cation
deficiencies at B-sites in AA′ B O -type perovskites have not
ACKNOWLEDGMENTS
■
Synchrotron radiation experiments were performed at SPring-8
with the approval of the Japan Synchrotron Radiation Research
Institute (Proposal Nos. 2010B1707, 2011B1009, 2011B1094,
and 2012A1660). Magnetic susceptibility measurements were
performed at the Institute for Solid State Physics, University of
Tokyo. This work was partly supported by JST-TRIP.
3
4
12
been reported to date, whereas cation deficiencies at A- and A′-
9
sites to maintain electric neutrality have. In the case of LCPO,
4
+
the robust valence state of Pt does not tolerate electron-
3
+
2+
doping introduced by substitution of La for Ca , so B-site
cation deficiencies maintain the electric neutrality of this
compound. It is interesting that deficiencies at different
crystallographic sites (A-, A′-, or B-sites) play a similar role in
keeping the charge balance of AA′ B O -type perovskites. The
REFERENCES
■
(
1) Imada, M.; Fujimori, A.; Tokura, Y. Rev. Mod. Phys. 1998, 70,
039−1263.
3
4
12
1
factor determining the deficient sites is not clear at this stage,
but our attempts to prepare A-site-deficient
(
2) Deschanvres, A.; Raveau, B.; Tollermer, M. Bull. Soc. Chim. Fr.
1967, 11, 4077−4078.
3) The crystal structure is drawn by using VESTA. Momma, K.;
Izumi, F. J. Appl. Crystallogr. 2008, 41, 653−658.
3
+
2 +
4 +
2 −
L a
C u
P t
O
a n d B - s i t e - d e fi c i e n t
2
/ 3
2+
3
4
1 2
(
3
+
4+
2−
La Cu 3Ti 3.75O
failed using high pressures of up to 15
12
GPa. Therefore, the preference for deficient sites may be
unique for each compound.
(
4) Subramanian, M. A.; Sleight, A. W. Solid State Sci. 2002, 4, 347−
3
51.
The probable origin of the short-range spin-glass-like
magnetic ordering of Cu spins in LCPO can be attributed to
B-site deficiencies. In CCPO, two kinds of magnetic exchange
interactions are proposed; one is an antiferromagnetic super-
exchange interaction via the Cu−O−Pt−O−Cu pathway and
the other is a direct ferromagnetic interaction between nearest-
neighboring Cu ions. The antiferromagnetic nature of CCPO
indicates that the former interaction dominates the latter in this
compound. However, in the case of LCPO, the antiferromag-
netic superexchange interaction seems to be randomly
disturbed by the B-site deficiencies because magnetic exhange
interaction does not likely work in the Cu−O−□−O−Cu
(5) Zeng, Z.; Greenblatt, M.; Subramanian, M. A.; Croft, M. Phys.
Rev. Lett. 1999, 82, 3164−3167.
(6) Alonso, J. A.; Sanchez-Benitez, J.; De Andres, A.; Martinez-Lope,
M. J.; Casais, M. T.; Martinez, J. L. Appl. Phys. Lett. 2003, 83, 2623−
2
625.
(
7) Kobayashi, W.; Terasaki, I.; Takeya, J.; Tsukada, I.; Ando, Y. J.
Phys. Soc. Jpn. 2004, 73, 2373−2376.
8) Yamada, I.; Tsuchida, K.; Ohgushi, K.; Hayashi, N.; Kim, J.; Tsuji,
12
(
N.; Takahashi, R.; Matsushita, M.; Nishiyama, N.; Inoue, T.; Irifune,
T.; Kato, K.; Takata, M.; Takano, M. Angew. Chem., Int. Ed. 2011, 50,
6
579−6582.
(9) Bochu, B.; Deschizeaux, M. N.; Joubert, J. C.; Collomb, A.;
Chenavas, J.; Marezio, M. J. Solid State Chem. 1979, 29, 291−298.
3
988
dx.doi.org/10.1021/ic302809v | Inorg. Chem. 2013, 52, 3985−3989

Inorganic Chemistry
Article
(
10) Dittl, A.; Krohns, S.; Sebald, J.; Schrettle, F.; Hemmida, M.; von
Nidda, H. A. K.; Riegg, S.; Reller, A.; Ebbinghaus, S. G.; Loidl, A. Eur.
Phys. J. B 2011, 79, 391−400.
(
11) Mizumaki, M.; Saito, T.; Shiraki, H.; Shimakawa, Y. Inorg. Chem.
2
(
009, 48, 3499−3501.
12) Yamada, I.; Takahashi, Y.; Ohgushi, K.; Nishiyama, N.;
Takahashi, R.; Wada, K.; Kunimoto, T.; Ohfuji, H.; Kojima, Y.;
Inoue, T.; Irifune, T. Inorg. Chem. 2010, 49, 6778−6780.
(
13) Izumi, F.; Momma, K. Solid State Phenom. 2007, 130, 15−20.
(
14) Escard, J.; Pontvianne, B.; Chenebaux, M. T.; Cosyns. J. Bull.
Soc. Chim. France 1975, 11, 2400−2408.
15) McGuinness, C.; Downes, J. E.; Sheridan, P.; Glans, P. A.;
Smith, K. E.; Si, W.; Johnson, P. D. Phys. Rev. B 2005, 71, 195111.
16) Ji, D. H.; Tang, G. D.; Li, Z. Z.; Han, Q. J.; Hou, X.; Bian, R. R.;
Liu, S. R. Appl. Phys. Lett. 2012, 111, 113902.
17) Brown, I. D.; Altermatt, D. Acta Crystallogr. 1985, B41, 244−
47.
18) The BVS were calculated using the following parameters: b =
(
(
(
2
(
0
3+
2+
0.37 for all atoms, r = 2.172 for La , r = 1.649 for Cu , and r =
0
0
0
4+
1.879 for Pt .
3
989
dx.doi.org/10.1021/ic302809v | Inorg. Chem. 2013, 52, 3985−3989