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Lanthanum strontium manganite (LSM or LSMO) is an oxide ceramic material with the general formula La1-xSrxMnO3, where ''x'' describes the doping level and for some applications it is in the range of 10-20%.〔(【引用サイトリンク】title=Lanthanum Strontium Manganite Supplier & Tech Info )〕 It has a perovskite-based crystal structure, which has the general form ABO3. In the crystal, the 'A' sites are occupied by lanthanum and strontium atoms, and the 'B' sites are occupied by manganese atoms. In other words, the material consists of lanthanum manganite with some of the lanthanum atoms substitutionally doped with strontium atoms. Alternatively the material can be considered as lanthanum manganite (LaMnO3) alloyed with strontium manganite (SrMnO3). LSMO has a rich electronic phase diagram, including a doping-dependent metal-insulator transition, paramagnetism and ferromagnetism. Evidence of the existence of a Griffith phase has been reported as well. LSM is black in color and has a density of approximately 6.5 gram/cm3.〔(Performance of Solid Oxide Fuel Cells with LSGM-LSM Composite Cathodes, J. Electrochem. Soc., Volume 149, Issue 12, pp. A1565-A1571 (2002) )〕 The actual density will vary depending on the processing method and actual stoichiometry. LSM is primarily an electronic conductor, with transference number close to 1. This material is commonly used in as a cathode material in commercially produced solid oxide fuel cells (SOFCs) because it has a high electrical conductivity at higher temperatures, and its thermal expansion coefficient is well matched with yttria-stabilized zirconia (YSZ), a common material for SOFC electrolytes. In research, LSM is one of the perovskite manganites that show the colossal magnetoresistance (CMR) effect,〔(A P Ramirez (1997) Colossal magnetoresistance. ''J. Phys.: Condens. Matter'' 9, 8171-8199. )〕 and is also an observed half-metal for compositions around ''x''=0.3.〔(J H Park ''et al'' (1998) Direct evidence for a half-metallic ferromagnet. ''Nature'' 392, 794-796. )〕 LSM behaves like a half-metal, suggesting its possible use in spintronics. It displays a colossal magnetoresistance effect. Above its Curie temperature (about 350K) Jahn-Teller polarons are formed; the material's ability to conduct electricity is dependent on the presence of the polarons.〔(【引用サイトリンク】title=Berkeley Lab View -- April 29, 2005 )〕 ==See also== * Solid oxide fuel cell 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「lanthanum strontium manganite」の詳細全文を読む スポンサード リンク
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