Low Temperature Electrical Transport in Double Layered CMR Manganite La1.2Sr1.4Ba0.4Mn2O7
The electrical transport behavior and magnetoresistance (MR) of a polycrystalline double layered manganite La1.2Sr1.4Ba0.4Mn2O7,synthesized by the sol-gel method,are investigated in the temperature range 4.2 K-300 K.The sample exhibits an insulator-to-metal transition at 87 K (TIM) and the spin-glass (SG)-like behavior is observed below 50 K (TsG).The transport behavior is analyzed in the entire temperature range considering three different regions:paramagnetic insulating region (T>TIM),ferromagnetic metallic region (TsG<T<TIM) and antiferromagnetic insulating region (T<TsG) by fitting the temperature dependent resistivity data to the equations governing the conduction process in the respective temperature regions.The results show that the conduction at T>TIM follows Mott variable range hopping (VRH) process,while the two-magnon scattering process is evidenced at TsG<T<TIM which is suppressed with the applied magnetic field of 4 T.The low temperature conductivity data are also fitted with Mott VRH equation.The sample exhibits a large MR (≈45%) over a temperature range 5 K-50 K and it shows ≈32% MR at 5 K with a magnetic field of 0.5 T.
Layered manganite Magnetoresistance Transport behavior Variable range hopping Magnon scattering
Y.S.Reddy P.Kistaiah C.Vishnuvardhan Reddy
Department of Physics Chaitanya Bharathi Institute of Technology, Gandipet Hyderabad, India Department of Physics Osmania University Hyderabad, India
国际会议
北京
英文
49-52
2012-10-26（万方平台首次上网日期，不代表论文的发表时间）