Transverse laser induced thermoelectric voltage effect in tilted La _(0.5)Sr_(0.5)CoO_3 thin films

摘要

The transverse laser induced thermoelectric voltage effect has been investigated in tilted La_(0.5)Sr_(0.5)CoO_3 thin films grown on vicinal cut LaAlO_3 (1 0 0) substrates when films are irradiated by pulse laser at room temperature. The detected voltage signals are demonstrated to originate from the transverse Seebeck effect as the linear dependence of voltage on tilted angle in the range of small tilted angle. The Seebeck coefficient anisotropy ΔS of 0.03 μV/K at room temperature is calculated and its distorted cubic structure is thought to be responsible for this. Films grown on a series of substrates with different tilted angles show the optimum angle of 19.8° for the maximum voltage. Film thickness dependence of voltage has also been studied.