A novel magnetoresistance induced by charge ordering in ferromagnetic/charge-ordered/ferromagnetic trilayers
1 Institude of Material Physics, Hangzhou Dianzi University - Hangzhou, Zhejiang, 310018, China
2 Department of Applied Physics, Nanjing University of Science and Technology - Nanjing, 210094, China
Received: 28 June 2015
Accepted: 18 October 2015
Microstructure, magnetoresistance (MR) and magnetic properties of Pr0.7Sr0.3MnO3/La0.5Ca0.5MnO3/Pr0.7Sr0.3MnO3 trilayers, which are shown to be tunable with different La0.5Ca0.5MnO3 spacer thickness, are investigated. The trilayer with 6 nm thick La0.5Ca0.5MnO3 spacer show at 195 K in 1 T and at 220 K in 9 T, which is realized through the double-exchange mechanism. In contrast, trilayers with the thicker La0.5Ca0.5MnO3 spacer show enhanced MR at a wide low-temperature range. The obtained at 50 K in 1 T in the trilayer with 18 nm thick La0.5Ca0.5MnO3 spacer is superior to that of other magnetic nanoscales. We surmise that this MR originates in the ferromagnetic/antiferromagnetic competition accompanied with the formation of a charge-ordered antiferromagnetic state and the collapse of the charge-ordered state at the applied magnetic field, rather than in the double-exchange mechanism. Large and tunable MR can be realized by controlling the strain state (the thickness of the La0.5Ca0.5MnO3 spacer), which can be applied in the used devices.
PACS: 75.47.Gk – Colossal magnetoresistance / 75.60.Ej – Magnetization curves, hysteresis, Barkhausen and related effects / 75.70.Cn – Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
© EPLA, 2015