Extensive study of giant magnetoresistance properties in half-metallic Co2(Fe,Mn)Si-based devices

Abstract

Fully epitaxial Co 2 Fe x Mn 1Àx Si(CFMS)/Ag/Co 2 Fe x Mn 1Àx Si current-perpendicular-to-plane giant magnetoresistive devices with various Fe/Mn ratios x and top CFMS layer thicknesses t CFMS were prepared. The highest magnetoresistance (MR) ratios, 58% at room temperature and 184% at 30 K, were observed in the sample with x ¼ 0.4 and t CFMS ¼ 3 nm. Enhancement of interface spinasymmetry was suggested for x ¼ 0.4 compared with that at x ¼ 0. A MR ratio of 58% was also observed even in a very thin trilayer structure, CFMS(4 nm)/Ag(3 nm)/CFMS(2 nm), which is promising for a next-generation magnetic read sensor for high-density hard disk drives. V

Equiatomic quaternary Heusler alloys: A material perspective for spintronic applications

“…High magnetoresistance (MR) ratios and large spin accumulation signals in spintronic devices using Co-based Heusler alloys clearly reflect the half-metallic nature of these alloys [17][18][19][20][21][22][23][24]. Recently, a very high value of spin polarization was observed for Co-based alloys at low temperatures, but a strong degradation in the transport properties was seen at room temperature [15,17,19,20].…”

“…HMF materials have potential applications as spin polarized current sources for current perpendicular to plane giant magnetoresistance (CPP-GMR) [17][18][19], magnetic tunnel junctions (MTJ) [20,21], non-local spin-valve (NLSV) devices [22,23] and spin injectors to semiconductors [24]. High magnetoresistance (MR) ratios and large spin accumulation signals in spintronic devices using Co-based Heusler alloys clearly reflect the half-metallic nature of these alloys [17][18][19][20][21][22][23][24].…”

Control of Magnetization Dynamics in Ordered Alloy Systems

“…Co2Fe0.4Mn0.6Si (CFMS) is another fullHeusler alloy exhibiting high spin polarization of conduction electrons. In fact, the CPP-GMR devices with CFMS | Ag | CFMS showed the MR ratios larger than CMS | Ag | CMS 24) . Thus, CFMS is also a candidate material for developing high performance STO 25,26) .…”

Interface Characterization of Current-Perpendicular-to-Plane Spin Valves Based on Spin Gapless Semiconductor Mn2CoAl

“…Sakuraba et al demonstrated an MR ratio of 58% at RT and 184% at 30 K in Co 2 Fe 0. 4 Mn 0.6 Si/Ag Co2Fe0.4Mn0.6Si/Ag CPP-SV [13]. Moreover, a number of CPP-SVs employing a Heusler alloy as the spin injector, such as Co2MnSi/Ag, Co2FeAl0.5Si0.5/Ag, and Co2FeGa0.5Ge0.5/Ag, also obtained high MR ratios [14,15].…”