We fabricated flexible spin valves on polyvinylidene fluoride（PVDF） membranes and investigated the influence of thermal deformation of substrates on the giant magnetoresistance（GMR） behaviors. The large magnetostr...We fabricated flexible spin valves on polyvinylidene fluoride（PVDF） membranes and investigated the influence of thermal deformation of substrates on the giant magnetoresistance（GMR） behaviors. The large magnetostrictive Fe_（81）Ga_（19）（Fe Ga） alloy and the low magnetostrictive Fe_（19）Ni_（81）（Fe Ni） alloy were selected as the free and pinned ferromagnetic layers.In addition, the exchange bias（EB） of the pinned layer was set along the different thermal deformation axes α_（31） or α_（32） of PVDF. The GMR ratio of the reference spin valves grown on Si intrinsically increases with lowering temperature due to an enhancement of spontaneous magnetization. For flexible spin valves, when decreasing temperature, the anisotropic thermal deformation of PVDF produces a uniaxial anisotropy along the α_（32） direction, which changes the distribution of magnetic domains. As a result, the GMR ratio at low temperature for spin valves with EB α_（32）becomes close to that on Si, but for spin valves with EB α_（31）is far away from that on Si. This thermal effect on GMR behaviors is more significant when using magnetostrictive Fe Ga as the free layer.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374312,51401230,51522105,and 51471101)the Ningbo Science and Technology Innovation Team,China(Grant No.2015B11001)
文摘We fabricated flexible spin valves on polyvinylidene fluoride（PVDF） membranes and investigated the influence of thermal deformation of substrates on the giant magnetoresistance（GMR） behaviors. The large magnetostrictive Fe_（81）Ga_（19）（Fe Ga） alloy and the low magnetostrictive Fe_（19）Ni_（81）（Fe Ni） alloy were selected as the free and pinned ferromagnetic layers.In addition, the exchange bias（EB） of the pinned layer was set along the different thermal deformation axes α_（31） or α_（32） of PVDF. The GMR ratio of the reference spin valves grown on Si intrinsically increases with lowering temperature due to an enhancement of spontaneous magnetization. For flexible spin valves, when decreasing temperature, the anisotropic thermal deformation of PVDF produces a uniaxial anisotropy along the α_（32） direction, which changes the distribution of magnetic domains. As a result, the GMR ratio at low temperature for spin valves with EB α_（32）becomes close to that on Si, but for spin valves with EB α_（31）is far away from that on Si. This thermal effect on GMR behaviors is more significant when using magnetostrictive Fe Ga as the free layer.
