Half-metallic magnetism and the search for better spin valves
arXiv:1407.5240 · doi:10.1063/1.4893969
Abstract
We use a previously proposed theory for the temperature dependence of tunneling magnetoresistance to shed light on ongoing efforts to optimize spin valves. First we show that a mechanism in which spin valve performance at finite temperatures is limited by uncorrelated thermal fluctuations of magnetization orientations on opposite sides of a tunnel junction is in good agreement with recent studies of the temperature-dependent magnetoresistance of high quality tunnel junctions with MgO barriers. Using this insight, we propose a simple formula which captures the advantages for spin-valve optimization of using materials with a high spin polarization of Fermi-level tunneling electrons, and of using materials with high ferromagnetic transition temperatures. We conclude that half-metallic ferromagnets can yield better spin-value performance than current elemental transition metal ferromagnet/MgO systems only if their ferromagnetic transition temperatures exceed .
arXiv comment7 pages, 4 figures, 2 tables
References in corpus (7)
- Half-metallic ferromagnets: From band structure to many-body effects
- Observation of spin-transfer switching in deep submicron-sized and low-resistance magnetic tunnel junctions
- Seebeck Effect in Magnetic Tunnel Junctions
- Band Structure and Transport Properties of CrO_2
- Half-Metallic Ferrimagnetism in Mn_2VAl
- Current-induced magnetization switching in MgO barrier based magnetic tunnel junctions with CoFeB/Ru/CoFeB synthetic ferrimagnetic free layer
- Giant thermoelectric effect in Al2O3 magnetic tunnel junctions