利用Rietveld分析方法对钙钛矿锰氧化物La1-xCaxMn0.96Fe0.04O3(x=0.31、0.5、0.6)室温下中子衍射实验数据进行拟合。结果表明,La1-xCaxMn0.96Fe0.04O3化合物具有MnO6八面体,空间群为Pnma,La(Ca)原子占据4c晶位,Mn(Fe)原子占据4b晶位,O...利用Rietveld分析方法对钙钛矿锰氧化物La1-xCaxMn0.96Fe0.04O3(x=0.31、0.5、0.6)室温下中子衍射实验数据进行拟合。结果表明,La1-xCaxMn0.96Fe0.04O3化合物具有MnO6八面体,空间群为Pnma,La(Ca)原子占据4c晶位,Mn(Fe)原子占据4b晶位,O原子分别占据4c和8d晶位。根据拟合结果,计算出Mn O键的键长和Mn O Mn的键角,并对该系列样品结构和磁性能间的关系进行了简单讨论。展开更多
The structure, magnetic and electric properties of Sr2FeMoO6 (the as-made sample) and samples after heat treatment were investigated. The nuclear and magnetic structures of the samples were studied using neutron powde...The structure, magnetic and electric properties of Sr2FeMoO6 (the as-made sample) and samples after heat treatment were investigated. The nuclear and magnetic structures of the samples were studied using neutron powder diffraction at room temperature. The results show that the tunneling magnetoresistance of polycrystalline Sr2FeMoO6 depends on its annealing temperature. Annealing at 800 ℃ makes the minimal magnetoresistance(MR) elevated, which may be due to the change of the grain size or the modified intergranular connections. Because of the impurity phase of Fe which probably affects the magnetotransport properties is much larger in sample C, so the MR is decreased by postannealing at 1100 ℃. Therefore, further enhancement of the tunneling magnetoresistance (TMR) can be realized by regulating the grain size at appropriate annealing temperature.展开更多
TL81 94021374三探头中子粉末衍射系统的研制[会,中]/马俊富,兰曼娜,姜枫(华南师范大学量子电子学研究所)//广东省光学学会第二届学术报告会.-广东韶关,93.7介绍了用386计算机进行运行控制和信息采集及处理的三探头中子粉末衍射仪系统...TL81 94021374三探头中子粉末衍射系统的研制[会,中]/马俊富,兰曼娜,姜枫(华南师范大学量子电子学研究所)//广东省光学学会第二届学术报告会.-广东韶关,93.7介绍了用386计算机进行运行控制和信息采集及处理的三探头中子粉末衍射仪系统的研究,在该项研究中仪器的总体性能已达到国外先进水平,该设备已成为我国重大技术援外项目之一,已在伊朗安装调试成功。(严兰)TL81 94021375常温核聚变现象实验研究=The progress in experimentalresearch of nuclear fusion at normaltemperature[刊,中]/王大伦,陈素和。展开更多
文摘利用Rietveld分析方法对钙钛矿锰氧化物La1-xCaxMn0.96Fe0.04O3(x=0.31、0.5、0.6)室温下中子衍射实验数据进行拟合。结果表明,La1-xCaxMn0.96Fe0.04O3化合物具有MnO6八面体,空间群为Pnma,La(Ca)原子占据4c晶位,Mn(Fe)原子占据4b晶位,O原子分别占据4c和8d晶位。根据拟合结果,计算出Mn O键的键长和Mn O Mn的键角,并对该系列样品结构和磁性能间的关系进行了简单讨论。
基金Project(1998061304) supported by the National Natural Foundation of China
文摘The structure, magnetic and electric properties of Sr2FeMoO6 (the as-made sample) and samples after heat treatment were investigated. The nuclear and magnetic structures of the samples were studied using neutron powder diffraction at room temperature. The results show that the tunneling magnetoresistance of polycrystalline Sr2FeMoO6 depends on its annealing temperature. Annealing at 800 ℃ makes the minimal magnetoresistance(MR) elevated, which may be due to the change of the grain size or the modified intergranular connections. Because of the impurity phase of Fe which probably affects the magnetotransport properties is much larger in sample C, so the MR is decreased by postannealing at 1100 ℃. Therefore, further enhancement of the tunneling magnetoresistance (TMR) can be realized by regulating the grain size at appropriate annealing temperature.
文摘TL81 94021374三探头中子粉末衍射系统的研制[会,中]/马俊富,兰曼娜,姜枫(华南师范大学量子电子学研究所)//广东省光学学会第二届学术报告会.-广东韶关,93.7介绍了用386计算机进行运行控制和信息采集及处理的三探头中子粉末衍射仪系统的研究,在该项研究中仪器的总体性能已达到国外先进水平,该设备已成为我国重大技术援外项目之一,已在伊朗安装调试成功。(严兰)TL81 94021375常温核聚变现象实验研究=The progress in experimentalresearch of nuclear fusion at normaltemperature[刊,中]/王大伦,陈素和。
