Powder samples with nominal composition La0.6Sr0.1TexMnO3 (x = 0.00, 0.05, 0.10, 0.15, 0.20) were prepared using the sol-gel method with thermal treatment up to 1473 K. On the basis of powder X-ray diffraction (XRD), thermogravimetric and magnetic measurements, it was found that almost all of the Te and a few of the Mn ions were lost from the samples when they were calcined at 1473 K. The reason for the Te loss and a quantitative phase analysis for the samples calcined at 1473 K are discussed in detail.
LI YanfengJI DenghuiZHAO ZhiweiTANG GuideLIU ShaopengZHANG YugeLI ZhuangzhiHOU DengluZHU Minggang
利用TaCl5-Ar-C3H6体系，采用X射线衍射技术和扫描电镜研究不同温度下化学气相沉积Tac涂层微观形貌及晶粒择优生长。结果表明：在800～1200℃时，随沉积温度升高，TaC颗粒从网球形逐渐转变为多角形以及金字塔形多面体，而其晶体择优取向依次从无明显择优取向向〈220〉和H〈200〉转变；利用牛长参数α和VAN DER DRIFT,MEAKIN的纳米级晶粒选择生长模型可较好地解释不同形貌的生长机制。当a=3时，薄膜会优先生长成〈200〉择优取向的金字塔品粒；当a=1．5时，则容易生长成〈220〉取向的多角形品粒。
The fact that there are Mn^(2+) at the A sites in the ABO_3 perovskite phase of manganites with the nominal composition La_(0.6-x)Nd_xSr_(0.1)MnO_3 showed by detailed experimental study and theoretical calculations.The magnetic moments of these Mn^(2+) are antiparallel to those of the Mn ions at the B sites.The content of the Mn^(2+) increases as the average ionic radius,,of the ions at A sites decreases,resulting in the experimentally observed phenomenon that the content of the Mn_3O_4 phase in the manganites decreases with decreasing .
