Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T07:09:15.879Z Has data issue: false hasContentIssue false

Anomalous phase composition in the two-phase region of DyFe3−xAlx (x≤1.0)

Published online by Cambridge University Press:  29 February 2012

Y. Q. Chen
Affiliation:
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
J. K. Liang*
Affiliation:
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China and International Center for Materials Physics, Academic Sinica, Shenyang 110016, China
J. Luo
Affiliation:
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
J. B. Li
Affiliation:
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
G. H. Rao
Affiliation:
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The structure transitions and phase relationships of DyFe3−xAlx compounds have been investigated by X-ray powder diffraction. Our XRD results show that each of the compounds with x≤0.45 crystallizes in the rhombohedral PuNi3-type structure with space group Rm and Z=9; for the 0.8≤x<1.0 compounds, each has a hexagonal structure of the CeNi3 type with space group P63/mmc and Z=6; and each of the samples with 0.45<x<0.8 is a two-phase mixture of the PuNi3- and CeNi3-type structures. The calculated XRD intensities of the DyFe3−xAlx compounds with x=0.2, 0.33, 0.4, and 0.45 indicate that Dy occupies the 3a and 6c sites, Fe and Al distribute randomly on the 18h site, and the 3b and 6c sites are exclusively occupied by Fe, which agrees well with those of our experimental XRD patterns. The XRD intensities of the DyFe3−xAlx compounds with x=0.8 and 1.0 have also been calculated and found to agree with the experimental results with Dy on the 2c and 4f sites, Fe and Al at the 12k site, and Fe at the 2a, 2b, and 2d sites. In the two-phase region with x=0.45–0.8, the values of unit-cell parameters and phase compositions are linearly dependent on the value of x, indicating that the two phases are constituted by the same composition x with different stacking arrangements. This abnormal two-phase equilibrium is further confirmed by the structural analysis of the DyFe2.33Al0.67 (or x=0.67) sample. The samples with x=1.1 and 1.2 were also analyzed, and each found to be a mixture of more than two phases.

Type
Technical Articles
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Burzo, E. (1983). “Magnetic properties of Gd(M xAl1−x)3 compounds with M=Fe or Co,” J. Magn. Magn. Mater. JMMMDC 31–34, 213214.10.1016/0304-8853(83)90220-2CrossRefGoogle Scholar
Burzo, E. and Seitabla, D. (1982). “Magnetic properties of Gd(FeyAl1−y)3 and (GdxY1−x)Fe3 compounds,” J. Phys. F: Met. Phys. JPFMAT 12, 26752685.10.1088/0305-4608/12/11/025CrossRefGoogle Scholar
Buschow, K. H. J. (1971). “Intermetallic compounds of rare earth elements and Ni, Co, or Fe,” Phys. Status Solidi A PSSABA 7, 199210.10.1002/pssa.2210070122CrossRefGoogle Scholar
Buschow, K. H. J. (1977). “Intermetallic compounds of rare-earth and 3d transition metals,” Rep. Prog. Phys. RPPHAG 40, 1179.10.1088/0034-4885/40/10/002CrossRefGoogle Scholar
Cromer, D. T. and Olsen, C. E. (1959). “The crystal structures of PuNi3 and CeNi3,” Acta Crystallogr. ACSEBH 12, 689694.10.1107/S0365110X59002006CrossRefGoogle Scholar
Dariel, M. P. and Erez, G. (1970). “Note on the structure of DyFe3 and Dy6Fe23,” J. Less-Common Met. JCOMAH 22, 360362.10.1016/0022-5088(70)90087-1CrossRefGoogle Scholar
Kirchmayr, H. R. and Poldy, C. A. (1978). “Magnetism in rare earth-3d intermetallics,” J. Magn. Magn. Mater. JMMMDC 8, 142.10.1016/0304-8853(78)90073-2CrossRefGoogle Scholar
Oesterreicher, H. (1976). “The strength of magnetic exchange in compounds TbFe2, TbFe3 and Tb2Fe17 with aluminum substitution for iron,” J. Less-Common Met. JCOMAH 46, 127132.10.1016/0022-5088(76)90185-5CrossRefGoogle Scholar
Oesterreicher, H. and Mcneely, D. (1977a). “Studies on compounds DyFe3, Dy6Fe23 and Dy2Fe17 with Al substitution for Fe II: Magnetic investigations,” J. Less-Common Met. JCOMAH 53, 245251.10.1016/0022-5088(77)90109-6CrossRefGoogle Scholar
Oesterreicher, H. and Mcneely, D. (1977b). “Studies on compounds DyFe3, Dy6Fe23 and Dy2Fe17 with Al substitution for Fe I: Structural investigations,” J. Less-Common Met. JCOMAH 53, 235243.10.1016/0022-5088(77)90108-4CrossRefGoogle Scholar
Oesterreicher, H. and Pitts, R. (1973). “Magnetic investigations on Tb0.25Fe0.75−xAlx and Tb0.105Fe0.895−xAlx,” J. Appl. Phys. JAPIAU 44, 5570.10.1063/1.1662198CrossRefGoogle Scholar
Pfranger, R. and Plusa, D. (1996). “Magnetic properties of the Dy(Fe1−xAlx)3,” Phys. Status Solidi A PSSABA 157, K17–K19.10.1002/pssa.2211570131CrossRefGoogle Scholar
Plusa, D. (1985). “Effect of aluminium on magnetic properties of DyFe3 compounds,” J. Magn. Magn. Mater. JMMMDC 51, 331336.10.1016/0304-8853(85)90032-0CrossRefGoogle Scholar
Rietveld, H. M. (1967). “Line profiles of neutron powder-diffraction peaks for structure refinement,” Acta Crystallogr. ACSEBH 22, 151152.10.1107/S0365110X67000234CrossRefGoogle Scholar
Rietveld, H. M. (1969). “A profile refinement method for nuclear and magnetic structures,” J. Appl. Crystallogr. JACGAR 2, 6571.10.1107/S0021889869006558CrossRefGoogle Scholar
Vegard, L. Z. (1921). “Die konstitution der mischkristalle und die raumfüllung der atone,” Z. Phys. ZEPYAA 5, 1726.10.1007/BF01349680CrossRefGoogle Scholar
Wang, B. W., Wu, C. H., Jin, X. M., Chuang, Y. C., and Li, J. Y. (1995). “Structure and magnetostriction of (Dy0.65Tb0.25Pr0.1) (Fe1−xAlx)3 alloys,” J. Alloys Compd. JALCEU 218, 2830.10.1016/0925-8388(94)01352-7CrossRefGoogle Scholar