Journal of Alloys and Compounds 270 (1998) 119–122
L
The crystal structure of HfZrP
*
Lingmin Zeng, Hugo F. Franzen
Ames Laboratory-DOE, Iowa State University, Ames, IA 50011, USA
Received 27 January 1998
Abstract
The crystal structure of HfZrP has been determined using single crystal X-ray diffraction data. This compound crystallizes in the
˚
orthorhombic space group Cmmm (No.65), with a519.004(3), b529.372(4), c53.565(1) A and the Zr2P structure type. The Hf and Zr
atoms are disordered on one site with total occupancy of 1.0. X-ray powder patterns indicate that (HfxZr12x)2P alloys consist of single
phase (Zr2P-type),two phases and single phase (Hf2P-type) corresponding to 0#x#0.5, 0.5,x,0.8 and 0.8#x#1.0, respectively.
1998 Elsevier Science S.A.
Keywords: Hafnium; Phosphorus; Zirconium; Crystal structure
1. Introduction
(HfxZr12x)2P samples (x50, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
0.7, 0.8, 0.9, 1.0) involved three major steps. In the first,
ZrP and HfP were prepared using the sealed tube method
described previously [13]. Mixtures of ZrP, Zr and Hf (or
HfP, Zr and Hf) in the different ratios were pelletized
under a pressure of 10 000 psi, and then arc melted three to
five times under an argon atmosphere. In the last step,
these alloys were encased in Ta foil and then sealed in a
evacuated fused silica tube and annealed at 10508C for 30
days.
The identification of the various phases present in each
sample was accomplished by examination of the X-ray
powder patterns (Guinier FR552 camera using Cu Ka
radiation). A needle-like single crystal from the sample
(Hf0.5Zr0.5)2P was selected and mounted on a glass fiber
for the structure determination. The crystal quality was
checked with a Weissenberg camera. The single-crystal
diffraction data were collected on a four-circle-diffrac-
tometer with a rotating anode (Rigaku AFC6R), using
monochromated Mo Ka radiation and the v/2u scan
technique. Three standard reflections monitored every 150
reflections showed no significant variation in intensity
throughout the data collection. The details of data collec-
tion are given in Table 1.
The binary Zr–P and Hf–P systems have been investi-
gated extensively. In the Zr–P system the compounds Zr3P
[1], Zr2P [2], Zr7P4 [3], Zr14P9 [4], ZrP [5,6] and ZrP2 [7]
have been reported and in the Hf–P system, there are
known phases with the chemical formulas Hf3P [8], Hf2P
[9], HfP [10], HfP2 [11] and Hf3P2 [12]. Comparing the
compounds in these two systems, we find there are
significant differences in their compositions and their
crystal structures. For example there are no Hf analogues
of a-ZrP, Zr7P4 and Zr14P9 and Hf3P2 has no Zr counter-
part as well. On the other hand, Hf2P crystallizes in the
Ta2P-type, whereas Zr2P crystallizes in Zr2P-type. In order
to add to our understanding of the behavior of Hf and Zr,
we studied a series of (HfxZr12x)2P alloys (0#x#1.0) and
report the crystal structure of HfZrP and the homogeneity
ranges of the solid solution phases.
2. Experimental details
The starting materials used in this experiment were red
phosphorus (powder, 2100 mesh, 99%, Alfa), hafnium
(powder, 2325 mesh, 99.6%, Alfa) and zirconium (pow-
der, 260 mesh, 99.7%, Alfa). The preparation of
The determination of the Laue group and the refinement
of the unit cell parameters were performed using
MSCIAFC diffractometer control software [14]. The crys-
tal structure was solved using the direct method with the
SHELXS program [15]. The structure was refined by
*
Corresponding author. Fax: 11 515 2945718.
0925-8388/98/$19.00
1998 Elsevier Science S.A. All rights reserved.
PII: S0925-8388(98)00522-2
Zeng, Lingmin
