Low Temperature Physics: 45, 789 (2019); https://doi.org/10.1063/1.5111308
Fizika Nizkikh Temperatur: Volume 45, Number 7 (July 2019), p. 921-927    ( to contents , go back )

Experimental observation of anomalies in the electrical, magnetic, and galvanomagnetic properties of cobalt-based Heusler alloys with variation of transition elements

Yu.A. Perevozchikova1, A.A. Semiannikova1, A.N. Domozhirova1, P.B. Terentyev1,3, E.B. Marchenkova1, E.I. Patrakov1, M. Eisterer2

P.S. Korenistov1,3, and V.V. Marchenkov1,3

1Институт физики металлов им. М.Н. Михеева УрО РАН ул. С. Ковалевской, 18, г. Екатеринбург, 620108, Россия

2Vienna University of Technology, Institute of Atomic and Subatomic Physics, 2 Stadionallee, Vienna 1020, Austria

3Уральский федеральный университет, ул. Мира, 19, г. Екатеринбург, 620002, Россия
E-mail: yu.perevozchikova@imp.uran.ru
march@imp.uran.ru

pos Анотація:

Received March 18, 2019 г., published online May 28, 2019

Abstract

A residual resistivity, a Hall effect and magnetization of Co2YSi Heusler alloys (Y = Ti, V, Cr, Mn, Fe, Co, Ni) were investigated at T = 4.2 K and in fields up to 100 kOe. Significant changes in the residual resistance ρ0, magnetization Ms, sign and magnitude of the normal R0 and anomalous RS coefficients of the Hall effect are shown to be observed with a change of the valence electron numbers z in the range from 26 to 32 corresponding the order from Co2TiSi to Co2NiSi. A clear correlation is observed between ρ0, R>sub>0, RS and Ms values, depending on the number z, which may be associated with the appearance of a state of a half-metallic ferromagnet and/or spin gapless semiconductor. When z is changed, a power-law dependence of the anomalous Hall effect coefficient on the residual electrical resistivity is found to be observed with the exponent k = 3.1, which disagrees with the existing theories, but agrees well with previously obtained experimental data in similar half-metallic ferromagnetic Heusler alloys.

Key words: half-metallic ferromagnets, spin gapless semiconductors, residual resistivity, magnetization, normal and anomalous Hall effect.

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