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Title: Metamagnetic phase transition in Nd{sub 1-x}Tb{sub x}Co{sub 2} compounds

Abstract

The electric resistivity and neutron diffraction measurements of the intermetallic compounds Nd{sub 1-x}Tb{sub x}Co{sub 2} (x = 0, 0.2, 0.3, 0.5, 0.7, or 1) have been performed. All compounds have a cubic structure at room temperature and a rhombohedral structure at 4.2 K. The magnetic structure of these compounds is described by the wave vector k = 0. The magnetizations of the rare earth and cobalt sublattices increase with increasing x. The concentration dependence of the cobalt sublattice magnetization is explained on the basis of the model of metamagnetic band subsystem in compounds of the RCo{sub 2} type.

Authors:
; ; ; ;  [1];  [2]
  1. Russian Academy of Sciences, Institute of Metal Physics, Ural Division (Russian Federation)
  2. Sungkyunkwan University, Department of Physics (Korea, Republic of)
Publication Date:
OSTI Identifier:
21090922
Resource Type:
Journal Article
Resource Relation:
Journal Name: Crystallography Reports; Journal Volume: 52; Journal Issue: 3; Other Information: DOI: 10.1134/S1063774507030133; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CUBIC LATTICES; ELECTRIC CONDUCTIVITY; INTERMETALLIC COMPOUNDS; MAGNETIZATION; NEODYMIUM ALLOYS; NEUTRON DIFFRACTION; PHASE TRANSFORMATIONS; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0273-0400 K; TERBIUM ALLOYS; TRIGONAL LATTICES

Citation Formats

Sherstobitova, E. A., E-mail: sherl@imp.uran.ru, Kozlov, K. A., Teplykh, A. E., Dorofeev, Yu. A., Skryabin, Yu. N., and Pirogov, A. N. Metamagnetic phase transition in Nd{sub 1-x}Tb{sub x}Co{sub 2} compounds. United States: N. p., 2007. Web. doi:10.1134/S1063774507030133.
Sherstobitova, E. A., E-mail: sherl@imp.uran.ru, Kozlov, K. A., Teplykh, A. E., Dorofeev, Yu. A., Skryabin, Yu. N., & Pirogov, A. N. Metamagnetic phase transition in Nd{sub 1-x}Tb{sub x}Co{sub 2} compounds. United States. doi:10.1134/S1063774507030133.
Sherstobitova, E. A., E-mail: sherl@imp.uran.ru, Kozlov, K. A., Teplykh, A. E., Dorofeev, Yu. A., Skryabin, Yu. N., and Pirogov, A. N. Tue . "Metamagnetic phase transition in Nd{sub 1-x}Tb{sub x}Co{sub 2} compounds". United States. doi:10.1134/S1063774507030133.
@article{osti_21090922,
title = {Metamagnetic phase transition in Nd{sub 1-x}Tb{sub x}Co{sub 2} compounds},
author = {Sherstobitova, E. A., E-mail: sherl@imp.uran.ru and Kozlov, K. A. and Teplykh, A. E. and Dorofeev, Yu. A. and Skryabin, Yu. N. and Pirogov, A. N.},
abstractNote = {The electric resistivity and neutron diffraction measurements of the intermetallic compounds Nd{sub 1-x}Tb{sub x}Co{sub 2} (x = 0, 0.2, 0.3, 0.5, 0.7, or 1) have been performed. All compounds have a cubic structure at room temperature and a rhombohedral structure at 4.2 K. The magnetic structure of these compounds is described by the wave vector k = 0. The magnetizations of the rare earth and cobalt sublattices increase with increasing x. The concentration dependence of the cobalt sublattice magnetization is explained on the basis of the model of metamagnetic band subsystem in compounds of the RCo{sub 2} type.},
doi = {10.1134/S1063774507030133},
journal = {Crystallography Reports},
number = 3,
volume = 52,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • The optical and magneto-optical properties of single crystals of YFe{sub 2}, CeFe{sub 2}, and Ce(Fe{sub 1-x}Co{sub x}){sub 2} (x{approx_equal}0.1) were measured between 1.4 and 5.0 eV using a rotating-analyzer ellipsometer and a normal-incidence polar Kerr spectrometer. The electronic structures and optical properties of YFe{sub 2} and CeFe{sub 2} were calculated using the tight-binding linear muffin-tin orbital method in the atomic-sphere approximation. For YFe{sub 2} the calculations reproduce the experimental spectra. Alloying CeFe{sub 2} with small amounts of Co leads to an electronic instability which is evidenced by a low-temperature antiferromagnetic (AF) phase. The Kerr effect was measured in the AFmore » and field-induced ferromagnetic (FM) regime. A remarkably large Kerr rotation was measured even in the AF state (up to -1 degree sign ). The phase transition from AF to FM order was observed in the Kerr rotation spectra at 5 and 50 K at photon energies of 1.8 and 4.0 eV. (c) 2000 The American Physical Society.« less
  • In this study, we report a morphotropic phase boundary (MPB) involved ferromagnetic system Tb 1-xNd xCo 2 and reveal the corresponding structural and magnetoelastic properties of this system. With high resolution synchrotron X-ray diffractometry, the crystal structure of the TbCo 2-rich side is detected to be rhombohedral and that of NdCo 2-rich side is tetragonal below their respective Curie temperatures TC. The MPB composition Tb 0.35Nd 0.65Co 2 corresponds to the coexistence of the rhombohedral phase (R-phase) and tetragonal phase ( T-phase). Contrary to previously reported MPB involved ferromagnetic systems, the MPB composition of Tb 0.35Nd 0.65Co 2 shows minimummore » magnetization which can be understood as compensation of sublattice moments between the R-phase and the T-phase. Furthermore, magnetostriction of Tb 1-xNd xCo 2 decreases with increasing Nd concentration until x = 0.8 and then increases in the negative direction with further increasing Nd concentration; the optimum point for magnetoelastic properties lies towards the rhombohedral phase. Finally, our work not only shows an anomalous type of ferromagnetic MPB but also provides an effective way to design functional materials.« less
  • In this work, we report a morphotropic phase boundary (MPB) involved ferromagnetic system Tb{sub 1-x}Nd{sub x}Co{sub 2} and reveal the corresponding structural and magnetoelastic properties of this system. With high resolution synchrotron X-ray diffractometry, the crystal structure of the TbCo{sub 2}-rich side is detected to be rhombohedral and that of NdCo{sub 2}-rich side is tetragonal below their respective Curie temperatures T{sub C}. The MPB composition Tb{sub 0.35}Nd{sub 0.65}Co{sub 2} corresponds to the coexistence of the rhombohedral phase (R-phase) and tetragonal phase (T-phase). Contrary to previously reported MPB involved ferromagnetic systems, the MPB composition of Tb{sub 0.35}Nd{sub 0.65}Co{sub 2} shows minimummore » magnetization which can be understood as compensation of sublattice moments between the R-phase and the T-phase. Furthermore, magnetostriction of Tb{sub 1-x}Nd{sub x}Co{sub 2} decreases with increasing Nd concentration until x = 0.8 and then increases in the negative direction with further increasing Nd concentration; the optimum point for magnetoelastic properties lies towards the rhombohedral phase. Our work not only shows an anomalous type of ferromagnetic MPB but also provides an effective way to design functional materials.« less
  • Ferrimagnetic Nd{sub 6}Fe{sub 14{minus}x}Al{sub x} compounds with x=3, 3.5, and 4 have been studied by magnetization measurements in fields up to 9 T. N{acute e}el temperatures were determined from M{umlt o}ssbauer spectra to be 308, 286, and 239 K, respectively. The net magnetization at T=4.2 K is 3.6 {mu}{sub B}/f.u.(x=3), 2.2 {mu}{sub B}/f.u.(x=3.5), and zero for x=4. Metamagnetic transitions were observed for all samples, at decreasing critical fields with increasing x. Both the metamagnetic transition hysteresis and the net magnetization decrease with increasing temperature and become negligible near 40 K. The initial susceptibility of Nd{sub 6}Fe{sub 10}Al{sub 4} shows anmore » anomalous temperature dependence near T=25 K, which might be associated with a spin reorientation. The electrical resistance of the latter compound, measured as a function of applied field, exhibits an abrupt 3{percent} increase at the metamagnetic transition. {copyright} {ital 1997 American Institute of Physics.}« less
  • The various magnetic structures and magnetic phase transitions in the series Nd{sub x}Tb{sub 1{minus}x}Mn{sub 2}Ge{sub 2} have been thoroughly studied by means of macroscopic magnetic and thermal measurements (such as magnetization, ac initial magnetic susceptibility and linear thermal expansion) and microscopic neutron-diffraction experiments. As a result, the magnetic phase diagram has been determined over the whole temperature range. Large changes in the local Mn magnetic moments (e.g., {Delta}{mu}{sub Mn}/{mu}{sub Mn}{approx}16{percent} in TbMn{sub 2}Ge{sub 2}) have been detected at the magnetic phase transitions observed at low temperatures, {approx}100{endash}140 K, in the x=0{endash}0.4 alloys. This variation, together with the appearance of magneticmore » ordering in the rare-earth sublattice, has been related to the volume anomalies found (e.g., {Delta}V/V{approx}0.3{percent} in TbMn{sub 2}Ge{sub 2}). A new magnetic structure of the Mn sublattice in the RMn{sub 2}X{sub 2} (R=rare earth, X=Si, Ge) family has been found in Nd{sub 0.4}Tb{sub 0.6}Mn{sub 2}Ge{sub 2} (140K{lt}T{lt}350 K) where two antiferromagnetic commensurate components within the (001) plane coexist with a ferromagnetic component along the c axis. The peculiar layered structure of the RMn{sub 2}Ge{sub 2} compounds favors a cancellation of the molecular field at the rare-earth sites in the case of antiferromagnetic arrangements of the Mn sublattice, effectively isolating the R atoms and making a paramagnetic behavior of these possible despite the presence of long-range order. The existence of a ferromagnetic component in the Mn sublattice has been concluded to be indispensable to allow the ordering of the rare-earth magnetic moments. {copyright} {ital 1997} {ital The American Physical Society}« less