Magnetic properties of Fe{sub 2}P-type R{sub 6}CoTe{sub 2} compounds (R=Gd-Er)

Journal Article · Tue Jun 15 04:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.04.002· OSTI ID:21421517

Mozharivskyj, Yu; Svitlyk, V ^[1]; Nirmala, R ^[2]; Isnard, O ^[3]; Manfrinetti, P; Provino, A ^[4]; Ritter, C ^[3]

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1. Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1 (Canada)
2. Indian Institute of Technology Madras, Chennai 600 036 (India)
3. Institute Laue-Langevin, 6 Rue J. Horowitz, 38042 Grenoble (France)
4. Dipartimento di Chimica, Universita di Genova, Via Dodecaneso 31, 16146 Genova (Italy)

The magnetic structure of the Fe{sub 2}P-type R{sub 6}CoTe{sub 2} phases (R=Gd-Er, space group P6-bar 2m) has been investigated through magnetization measurement and neutron powder diffraction. All phases demonstrate high-temperature ferromagnetic and low-temperature transitions: T{sub C}=220 K and T{sub CN}=180 K for Gd{sub 6}CoTe{sub 2}, T{sub C}=174 K and T{sub CN}=52 K for Tb{sub 6}CoTe{sub 2}, T{sub C}=125 K and T{sub CN}=26 K for Dy{sub 6}CoTe{sub 2}, T{sub CN}=60 K and T{sub N}=22 K for Ho{sub 6}CoTe{sub 2} and T{sub CN{approx}}30 K and T{sub N{approx}}14 K for Er{sub 6}CoTe{sub 2}. Between 174 and 52 K Tb{sub 6}CoTe{sub 2} has a collinear magnetic structure with K{sub 0}=[0, 0, 0] and with magnetic moments along the c-axis, whereas below 52 K it adopts a non-collinear ferromagnetic one. Below 60 K the magnetic structure of Ho{sub 6}CoTe{sub 2} is that of a non-collinear ferromagnet. The holmium magnetic components with a K{sub 0}=[0, 0, 0] wave vector are aligned ferromagneticaly along the c-axis, whereas the magnetic component with a K{sub 1}=[1/2, 1/2, 0] wave vector are arranged in the ab plane. The low-temperature magnetic transition at {approx}22 K coincides with the reorientation of the Ho magnetic component with the K{sub 0} vector from the collinear to the non-collinear state. Below 30 K Er{sub 6}CoTe{sub 2} shows an amplitude-modulate magnetic structure with a collinear arrangement of magnetic components with K{sub 0}=[0, 0, 0] and K{sub 1}=[1/2, 1/2, 0]. The low-temperature magnetic transition at {approx}14 K corresponds to the variation in the magnitudes of the M{sub Er}{sup K0} and M{sub Er}{sup K1} magnetic components. In these phases, no local moment was detected on the cobalt site. The magnetic entropy of Gd{sub 6}CoTe{sub 2} increases from {Delta}S{sub mag}=-4.5 J/kg K at 220 K up to {Delta}S{sub mag}=-6.5 J/kg K at 180 K for the field change {Delta}{mu}{sub 0}H=0-5 T. - Graphical abstract: The novel Fe{sub 2}P-type R{sub 6}CoTe{sub 2} phases (R=Gd-Er, space group P6-bar 2m) show ferromagnetic type ordering in the temperature range 14-220 K.All compounds demonstrate high-temperature ferromagnetic and low-temperature antiferromagnetic ordering.The magnetic entropy of Gd{sub 6}CoTe{sub 2} increases from {Delta}S{sub mag}=-4.5 J/kg K at 220 K up to {Delta}S{sub mag}=-6.5 J/kg K at 180 K for the field change {Delta}{mu}{sub 0}H=0-5 T.The R{sub 6}CoTe{sub 2} compounds exhibit the commensurate magnetic structures with wave vectors K{sub 0}=[0, 0, 0] and K{sub 1}=[1/2, 1/2, 1/2].

• OSTI ID: 21421517
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 6 Vol. 183; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ANTIFERROMAGNETISM
CHALCOGENIDES
COBALT COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
ENTROPY
INTERMETALLIC COMPOUNDS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETISM
MAGNETIZATION
NEUTRON DIFFRACTION
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SPACE GROUPS
SYMMETRY GROUPS
TELLURIDES
TELLURIUM COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS