Electrical resistivities of $\gamma$-phase $Fe_xNi_{80-x}Cr_{20}$ alloys

Banerjee, S and Raychaudhuri, AK (1994) Electrical resistivities of $\gamma$-phase $Fe_xNi_{80-x}Cr_{20}$ alloys. In: Physical Review B, 50 (12). pp. 8195-8206.

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Abstract

In this paper we present a comprehensive investigation of electrical resistivities [\rho(T)] of the γ-phase pseudobinary Fe alloy series $Fe_xNi_{80-x}Cr_{20}$ in the temperature range 0.4–300 K. These alloys exhibit exotic magnetic behavior at and near the critical composition for ferromagnetism $x_c\simeq 59-63.$ Special attention has been given to the critical region $(x\simeqx_c)$ where we find sharp changes in $p_0$ (zero temperature resistivity) as well as in the temperature dependence of \rho(T). These observations have been explained as arising due to the absence of long-range magnetic order and a change in effective carrier concentration at $x\simeqx_c.$ For all x (≤66) these alloys exhibit a resistivity minimum at $T=T_{min}.$ $T_{min}$ continuously decreases from approximately 35 K for $x\approx12$ to approximately 6 K for $x\approx59.$ \rho(T) for $T<T_{min}$ shows a rise $(p{\sim}- \sqrt{T})$ that does not depend on the magnetic state of the alloy. For $T_{min}<T<80 K,\hspace{2mm}p(T)$ away from $x_c$ follows a predominantly $T^2$ dependence arising from electron–spin-wave scattering which shows a drastic reduction for $x\simeqx_c.$ We also compare our data with an $\alpha$-phase $Fe_{25}Cr_{75}$ alloy.

Item Type: Journal Article The copyright belongs to American Physical Society. Division of Physical & Mathematical Sciences > Physics 22 Nov 2007 19 Sep 2010 04:29 http://eprints.iisc.ernet.in/id/eprint/7758