Large linear magnetoresistivity in strongly inhomogeneous planar and layered systems

TL;DR

This paper derives explicit formulas for magnetoresistance in strongly inhomogeneous two-phase systems, revealing large linear magnetoresistance effects that match experimental data and suggesting applications in magnetic sensors.

Contribution

It provides exact dual transformation-based expressions for magnetoresistance in inhomogeneous media, applicable at arbitrary concentrations and magnetic fields, with physical explanations and practical implications.

Findings

Large linear magnetoresistance observed in inhomogeneous media.

Formulas match experimental data on silver chalcogenides.

Stripe-like inhomogeneities are promising for sensor applications.

Abstract

Explicit expressions for magnetoresistance $R$ of planar and layered strongly inhomogeneous two-phase systems are obtained, using exact dual transformation, connecting effective conductivities of in-plane isotropic two-phase systems with and without magnetic field. These expressions allow to describe the magnetoresistance of various inhomogeneous media at arbitrary concentrations $x$ and magnetic fields $H$. All expressions show large linear magnetoresistance effect with different dependencies on the phase concentrations. The corresponding plots of the $x$- and $H$-dependencies of $R(x,H)$ are represented for various values, respectively, of magnetic field and concentrations at some values of inhomogeneity parameter. The obtained results show a remarkable similarity with the existing experimental data on linear magnetoresistance in silver chalcogenides $Ag_{2+\delta}Se.$ A possible physical explanation of this similarity is proposed. It is shown that the random, stripe type, structures of inhomogeneities are the most suitable for a fabrication of magnetic sensors and a storage of information at room temperatures.