Pseudo spin valves based on L10 (111)-oriented FePt fixed layers with tilted anisotropy

We demonstrate magnetoresistance (MR) in excess of 4% in FePt/CoFe/Cu/CoFe/NiFe pseudo spin valves based on L10 (111)-oriented FePt fixed layers with a 36° out-of-plane tilted magnetization. The high MR is achieved by increasing the spin polarization at the Cu interfaces, using thin CoFe, and optimizing the FePt growth and Cu interface quality using Ta and Ta/Pt underlayers. We observe well-separated switching of the FePt/CoFe fixed layer and the CoFe/NiFe free layer, suggesting that CoFe is rigidly exchange coupled to FePt and NiFe in the respective layers.

[1]  Yan Zhou,et al.  Pseudo-spin-valve with L10 (111)-oriented FePt fixed layer , 2009 .

[2]  Johan Åkerman,et al.  Spin torque oscillator frequency versus magnetic field angle: The prospect of operation beyond 65 GHz , 2009 .

[3]  Yan Zhou,et al.  Microwave generation of tilted-polarizer spin torque oscillator , 2009 .

[4]  R. Sbiaa,et al.  Spin transfer switching enhancement in perpendicular anisotropy magnetic tunnel junctions with a canted in-plane spin polarizer , 2009 .

[5]  Jian-Gang Zhu,et al.  Magnetoresistive Random Access Memory: The Path to Competitiveness and Scalability , 2008, Proceedings of the IEEE.

[6]  Yan Zhou,et al.  Spin-torque oscillator with tilted fixed layer magnetization , 2008 .

[7]  W. Rippard,et al.  Developments in nano-oscillators based upon spin-transfer point-contact devices , 2008 .

[8]  J. Katine,et al.  Device implications of spin-transfer torques , 2008 .

[9]  A. Fert,et al.  The emergence of spin electronics in data storage. , 2007, Nature materials.

[10]  Zongzhi Zhang,et al.  Pinning effect and thermal stability study in L10 FePt-pinned spin valves , 2007 .

[11]  J. Zhu,et al.  Spin Torque and Field-Driven Perpendicular MRAM Designs Scalable to Multi-Gb/Chip Capacity , 2006, IEEE Transactions on Magnetics.

[12]  T. Gao,et al.  L10 FePt films deposited on pyramid-type Si substrate for perpendicular magnetic recording media , 2006 .

[13]  Kay Yakushiji,et al.  Spin-polarized current-induced magnetization reversal in perpendicularly magnetized L10-FePt layers , 2006 .

[14]  T. Chong,et al.  Approaches to tilted magnetic recording for extremely high areal density , 2003 .

[15]  Tow Chong Chong,et al.  Tilted media in a perpendicular recording system for high areal density recording , 2003 .

[16]  H. N. Bertram,et al.  Magnetic recording configuration for densities beyond 1 Tb/in/sup 2/ and data rates beyond 1 Gb/s , 2002 .

[17]  D. Weller,et al.  Magnetic, structural and microstructural properties of FePt/M (M=C,BN) granular films , 2001 .

[18]  K. Shin,et al.  Controlling the crystallographic orientation in ultrathin L1/sub 0/ FePt[111] films on MgO[111] underlayer , 2001 .

[19]  Ralph,et al.  Current-driven magnetization reversal and spin-wave excitations in Co /Cu /Co pillars , 1999, Physical review letters.

[20]  Berger.  Emission of spin waves by a magnetic multilayer traversed by a current. , 1996, Physical review. B, Condensed matter.

[21]  J. Slonczewski.  Current-driven excitation of magnetic multilayers , 1996 .