Transport properties of high-performance all-Heusler Co2CrSi/Cu2CrAl/Co2CrSi giant magnetoresistance device

Transport properties of giant magnetoresistance (MR) junction consisting of trilayer Co2CrSi/Cu2CrAl/Co2CrSi Heusler alloys (L21) are studied using first-principles approach based on density functional theory and the non-equilibrium Green's function method. Highly conductive channels are found in almost the entire k-plane when the magnetizations of the electrodes are parallel, while they are completely blocked in the antiparallel configuration, which leads to a high magnetoresistance ratio (the pessimistic MR ratio is nearly 100%). Furthermore, the calculated I-V curve shows that the device behaves as a good spin valve with a considerable disparity in currents under the parallel and antiparallel magnetic configurations of the electrodes. The Co2CrSi/Cu2CrAl/Co2CrSi junction could be useful for high-performance all-metallic current-perpendicular-to-plane giant magnetoresistance reading head for the next generation high density magnetic storage.

[1]  C. Felser,et al.  Heusler Compounds—A Material Class With Exceptional Properties , 2011, IEEE Transactions on Magnetics.

[2]  K. Hono,et al.  Current-perpendicular-to-plane spin valves with a Co2Mn(Ga0.5Sn0.5) Heusler alloy , 2010 .

[3]  M. Shirai,et al.  Mechanism of large magnetoresistance in Co 2 MnSi / Ag / Co 2 MnSi devices with current perpendicular to the plane , 2010 .

[4]  G. Han,et al.  The band structure-matched and highly spin-polarized Co2CrZ/Cu2CrAl Heusler alloys interface , 2009 .

[5]  Xilin Peng,et al.  “All-Heusler alloy” current-perpendicular-to-plane giant magnetoresistance , 2009 .

[6]  K. Hono,et al.  Current-perpendicular-to-plane giant magnetoresistance in spin-valve structures using epitaxial Co2FeAl0.5Si0.5/Ag/Co2FeAl0.5Si0.5 trilayers , 2008 .

[7]  H. Uchida,et al.  Half-metallic interface and coherent tunneling inCo2YZ/MgO/Co2YZ(YZ=MnSi,CrAl)magnetic tunnel junctions: A first-principles study , 2008 .

[8]  Hitoshi Iwasaki,et al.  The applicability of CPP-GMR heads for magnetic recording , 2002 .

[9]  N. Papanikolaou,et al.  Slater-Pauling behavior and origin of the half-metallicity of the full-Heusler alloys , 2002 .

[10]  Hitoshi Iwasaki,et al.  Output enhancement of spin-valve giant magnetoresistance in current-perpendicular-to-plane geometry , 2002 .

[11]  I. Galanakis.  Surface properties of the half-and full-Heusler alloys , 2002, cond-mat/0204083.

[12]  P. Ordejón,et al.  Density-functional method for nonequilibrium electron transport , 2001, cond-mat/0110650.

[13]  Jian Wang,et al.  Ab initio modeling of open systems: Charge transfer, electron conduction, and molecular switching of a C 60 device , 2000, cond-mat/0007176.

[14]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[15]  Fert,et al.  Theory of the perpendicular magnetoresistance in magnetic multilayers. , 1993, Physical review. B, Condensed matter.