Noncontact GMR measurements of synthetic spin valves using IR reflection spectroscopy

Abstract

Abstract-The magnetorefractive effect has been used in infrared reflection spectroscopy to study the magnetotransport properties of synthetic spin valves. This optical noncontact technique shows excellent correlation with the electrical giant magnetoresistance data.Index Terms-Giant magnetoresistance (GMR), infrared (IR) reflection spectroscopy, magnetorefractive effect (MRE), synthetic spin valves.

Modelling the magnetorefractive effect in giant magnetoresistive granular and layered materials

“…Following its first discovery using Ni 80 Fe 20 /Cu/Co/Cu multilayers in transmission experiments [1], infrared-wavelength MRE measurements have been extended to the reflection geometry [4,5], contributions to the effect from interband transitions [6] and phonon modes have been identified [7], and MRE results compared to magnetic-linear-dichroism and emissivity studies [8,9]. The wide applicability has been demonstrated in studies of the transport properties of GMR granular [5,10], multilayer [11], spin-valve [8,12] thin films, LaSrMnO perovskites [13] and granular metal-insulator systems [14][15][16].…”

Active photonic platforms for the mid-infrared to the THz regime using spintronic structures

“…granularly alloyed CoAg films [32,33,55]; or spin valves with CoFe ferromagnetic layers [39,56,57]; and others [37,58]. In nearly all these systems the strength of the magnetic field that is needed to change the relative orientation of the magnetization of the ferromagnetic entities (i.e.…”

Infrared metrology for spintronic materials and devices

“…Infrared (IR) measurements of 0957-0233/09/045109+05$30.00 the magneto-resistance have been previously reported [8][9][10][11][12][13] and they are based on the IR magneto-refractive effect (MRE) first proposed in 1995 [14]. The first measurements were made using an IR Fourier transform spectrometer in reflection geometry to study a range of spin valve and GMR systems [16,17]. Single wavelength experiments using an IR CO 2 laser [15] more closely mimicked an electrical GMR measurement, and recently an IR optical fibre instrument has been proposed [18] and successfully tested on a GMR multilayer sample [19,20].…”