【摘要】 采用新型渠道火花烧蚀技术在LaAlO3(001)基片上生长了La0.7Sr0.3MnO3(LSMO)薄膜。X射线衍射对样品结构的分析表明,制备的LSMO薄膜具有c轴取向生长的特点,薄膜与基片间因晶格不匹配而受面内应力挤压,发生弛豫而出现两相。在室温下采用振动样品磁强计测试样品的面内方向磁滞回线,表明制备的LSMO样品具有软磁性,矫顽力Hc=13Oe。通过标准四探针法测量了LSMO薄膜的室温薄膜电阻与外加磁场的关系,得知零场电阻率ρ(0)=19.4 mΩ.cm,室温下4800Oe外场作用下的磁电阻变化率为2.25%,对此用双交换作用机制定性地加以了解释。更多还原

【Abstract】 La0.7Sr0.3MnO3(LSMO) thin films were deposited on LaAlO3(LAO)(001) by means of channel spark ablation.X-ray diffraction pattern shows that the LSMO thin films are highly c-axis oriented.The lattice mismatch between LSMO and LAO has compressive strain in-plane and stretching the lattice along c-axis,which resulting in appearence of two phases in the sample.The magnetic hysteresis and electric resistance were investigated by a VSM magnetometer and the standard four probe measurement,respectively.At room temperature the film has characteristics of a soft magnet with a coercivity of 13 Oe.The zero-field resistivity ρ(0) is 19.4 mΩ·cm and the magnetoresistance value under 4800 Oe at T = 305 K is 2.25 %.Double exchange mechanism is used to qualitatively account for the magnetoresistance effect.更多还原