巨大磁気抵抗薄膜の微細構造観察 [in Japanese] Observation of Microstructure in Colossal Magnetoresistance Thin Films [in Japanese]
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We observed the microstructure of perovskite thin films, and compared the results with their colossal magnetoresistance (CMR) properties. Epitaxial or textured films of La<SUB>1-x</SUB>Sr<SUB>x</SUB>Mn<SUB>y</SUB>O<SUB>3-δ</SUB>were prepared by rf sputtering on (100)SrTiO<SUB>3</SUB> and (110)sapphire single crystal substrates. The films were investigated by X-ray diffraction, magnetoresistance measurement, and transmission electron microscopy (TEM). The magnetoresistance of the films deposited on SrTiO<SUB>3</SUB> substrate shows similar temperature dependence to that of bulk single crystals. The temperature dependence of the magnetresistance in the films on a sapphire substrate is different from that in bulk single crystals, that is, the magnetoresistance decrease monotonously with increasing temperature. We revealed by TEM observations that the films on SrTiO<SUB>3</SUB> substrate grew epitaxially with a number of defects, however, the films on sapphire substrate grew with a columnar structure and showed no epitaxy. Therefore, the difference in the MR properties is attributed to the lattice mismatch between films and substrates.
- J. Jpn. Soc. Powder Powder Metallurgy
J. Jpn. Soc. Powder Powder Metallurgy 46(2), 147-150, 1999-02-15
Japan Society of Powder and Powder Metallurgy