Electrochromic WO_(3-x) and colossal magnetoresistive (La,Sr)MnO_3 perovskite oxide thin films by pulsed laser deposition

摘要

The functional oxide thin films of electrochromic WO_(3-x) and colossal magnetoresistive La_(0.8)Sr_(0.2)MnO_3 were prepared by a KrF excimer pulsed laser deposition technique.Optical transprancy and electrical conductivity of the WO_(3-x) film were changed by the oxygen content in the lattice.Triclinic,tetragonal and amorphous WO_(3-x) films were prepared by adjusting the oxygen atmosphere during the deposition.We revealed that relationship between the crystal structure and the gas sensing property of the films.The triclinic WO_(3-x) films (1 mum) showed the high sensitivity to NO (60 ppm) gas at an operating temperature of 150 degC.The colossal magnetoresistive La_(0.8)Sr_(0.2)MnO_3 thin films having the MR ratio of 15% (H=7 kG) was deposited under the conditions of the laser energy density of 2J/cm~2 (5Hz),substrate temperature of 850 degC and oxygen pressure of 500 mTorr.The magnetic sensor composing of the La_(0.8)Sr_(0.2)MnO_3 thin film responded to the AC magnetic field (1 kHz).