共查询到18条相似文献,搜索用时 62 毫秒
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采用溶胶-凝胶法制备了单相Bi0.95 Eu0.05Fe0.95 Co0.05 O3纳米粉末。用X射线衍射仪(XRD)和扫描电子显微镜(SEM)测量分析了其结构和形貌,结果表明样品仍为钙钛矿菱方结构。样品Fe2p的X射线吸收谱(XAS)表明样品中Fe的价态处于Fe2+和Fe3+的混合态。利用振动样品磁强计(VSM)测量样品的磁性特征,结果表明样品具有完整闭合的磁滞回线,表现出室温的铁磁性,相比BiFeO3样品磁性得到明显增强。 相似文献
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《功能材料信息》2017,(4)
利用高温高压技术制备了Bi_(0.95)La_(0.05)Fe_1-_xCo_xO_3(x=0,0.1,0.2)陶瓷样品。研究了La和Co共掺杂对BiFeO_3的物相结构及多铁性能的影响。结构分析表明,所有样品均为菱方钙钛矿结构,同时Co掺杂引起一定的结构畸变。Co掺杂导致Bi_(0.95)La_(0.05)FeO_3中空间调制的螺旋磁结构转变为共线的G型反铁磁结构,从而导致样品室温磁性能得到明显提高。样品中介电常数随着外加磁场的增加而增加,表明在Co掺杂Bi_(0.95)La_(0.05)FeO_3陶瓷中存在磁电耦合效应。在796 kA/m外加磁场及3k Hz频率下,Bi_(0.95)La_(0.05)Fe_(0.9)Co_(0.1)O_3和Bi_(0.95)La_(0.05)Fe(0.8)Co_(0.2)O_3的磁介电系数分别为1.61%和1.75%。 相似文献
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采用溶胶-凝胶法制备了La0.05Eu0.05Bi0.9Fe0.95Co0.05O3和Eu0.1Bi0.9Fe0.95Co0.05O3样品,利用XRD技术对样品的结构进行了表征;采用MPMS(SQUID)VSM系统对样品的铁磁性进行了测量;采用同步辐射XAFS实验技术对样品的局域结构进行了测量。结果显示,三元共掺样品的磁性较纯相BiFeO3有近2个数量级的增强。通过对实验数据的分析,得出了三元共掺BiFeO3样品铁磁性提高是由于晶格的微小改变引起磁性离子之间夹角改变,进而造成磁矩排列的改变引起的。 相似文献
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《功能材料》2017,(6)
利用高温高压技术制备了Bi_(0.95)La_(0.05)Fe_(1-x)Co_xO_3(x=0,0.1,0.2)陶瓷样品。研究了La和Co共掺杂对BiFeO_3的物相结构及多铁性能的影响。结构分析表明,所有样品均为菱方钙钛矿结构,同时Co掺杂引起一定的结构畸变。Co掺杂导致Bi_(0.95)La_(0.05)FeO_3中空间调制的螺旋磁结构转变为共线的G型反铁磁结构,从而导致样品室温磁性能得到明显提高。样品中介电常数随着外加磁场的增加而增加,表明在Co掺杂Bi_(0.95)La_(0.05)FeO_3陶瓷中存在磁电耦合效应。在796kA/m外加磁场及3kHz频率下,Bi_(0.95)La_(0.05)Fe_(0.9)Co_(0.1)O_3和Bi_(0.95)La_(0.05)Fe_(1-x)Co_xO_3的磁介电系数分别为1.61%和1.75%。 相似文献
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采用溶胶-凝胶法成功制备了Bi1-xLaxFe0.99Nb0.01O3(x≤0.25)纳米颗粒样品,并研究了La和Nb共掺对BiFeO3样品的晶体结构、晶粒尺寸和磁学性质的影响.根据X射线衍射及Rietveld精修结果可知,所有样品都保持R3c空间结构,且Fe-O-Fe键角随着La掺杂量的增加而减小.XPS测试结果表明,La和少量Nb共掺不会引起样品中Fe3+和Fe2+含量的明显变化.磁性测量发现剩余磁化强度强烈依赖于La掺杂量x.La掺杂影响着反向旋转的FeO5八面体结构变化,而Nb离子掺杂会导致样品晶粒细化.共掺BiFeO3的磁性增强是两种影响机制协同作用的结果. 相似文献
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采用磁控溅射的方法在SrRuO3(SRO)/SrTiO3(001)衬底上外延生长BiFe0.95Mn0.05O3(BFMO)薄膜,研究沉积温度对BiFe0.95Mn0.05O3薄膜结构、铁电性能、漏电流及疲劳保持特性的影响。X射线衍射图谱显示在780℃生长的BiFe0.95Mn0.05O3薄膜结构良好、无杂相峰。在此温度下,SRO/BFMO/SRO异质结电容器剩余极化强度P r最高,为115μC/cm2,矫顽场Ec约为128 kV/cm,电容器漏电流密度随着生长温度的升高而增大。BiFe0.95Mn0.05O3薄膜电容器在经过1010次极化反转和104s的保持时间后表现出良好的抗疲劳特性和保持特性。 相似文献
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G. K. Safaraliev Yu. N. Emirov M. K. Kurbanov T. I. Isabekova 《Inorganic Materials》2000,36(10):1018-1019
The effect of laser irradiation on the photoluminescence of (SiC)0.95(A1N)0.05 epitaxial films was studied. Irradiation was found to dislodge Al and N atoms from their substitutional sites, producing
radiative donor-acceptor pairs Alsi-Nc. The average pair separation decreases with increasing irradiation time, as evidenced by the shift of the corresponding emission
to higher energies. 相似文献
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Mahmoud Aly Hamad 《Journal of Superconductivity and Novel Magnetism》2013,26(2):449-453
In this paper, a phenomenological model is used to calculate magneto-caloric properties of Ge0.95Mn0.05 films fabricated with substrate temperatures of 85, 100, and 120 °C. Calculations showed that the ferromagnetic Mn5Ge3 phase improves magneto-caloric properties of the Ge0.95Mn0.05 films. It is suggested that Ge0.95Mn0.05 films are suitable candidates as refrigerants near room-temperature region. 相似文献
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Hongtao Yu Jilin Cheng Wenbo Zhang Jingsong Liu Guangliang Xu 《Journal of Materials Science: Materials in Electronics》2012,23(2):572-575
The microwave dielectric properties of (1−x)Mg(Zr0.05Ti0.95)O3-xSrTiO3 ceramics prepared by conventional solid processing were investigated. With increasing x, the dielectric constant and the
quality factor decreased, and the temperature coefficient of resonant frequency was tuned from negative to positive value.
The effect of sintering temperature on microwave properties was also studied. After sintering at 1,390 °C for 4 h, the ceramics
exhibited a near zero temperature coefficient of resonant frequency about 2.1 ppm/°C, an optimum dielectric constant of 20.9
and a high quality factor of 203000 (6.8 GHz), at the level of x = 0.05. 相似文献
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I. V. F. Viney B. Ray J. W. Brightwell B. W. Arterton A. C. Wright 《Journal of Materials Science: Materials in Electronics》1996,7(4):305-308
Cadmium-doped calcium sulphide has great potential as a broadband light source in both powder and thin film electroluminescent devices. We now report the first structural investigation of polycrystalline cadmium-doped calcium sulphide using a combination of transmission electron microscopy (TEM) with microanalysis, and X-ray diffraction. We show that the crystals formed by direct reaction of CaS and CdS under excess sulphur do not yield an even distribution of cadmium. We also show that the crystals are heavily dislocated with defect structures typical of rock-salt structures. We show that TEM can be successfully applied to the study of these moisture-sensitive materials without the formation of artefacts and that TEM should be a valuable tool for studying their thin film structures. 相似文献
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以ZrO2、Pb304和TiO2为原料(Nb2O5为掺杂剂),采用柱面冲击波装置合成了Pb(Zr0.95 Ti0.05)O2(PZT95/5)粉体,并对粉体活性及其烧结性能进行了研究。XRD及SEM分析表明,利用冲击波的高温高压作用可以合成单一钙钛矿相PZT95/5粉体,并使得粉体发生了晶粒细化与晶格畸变,这有利于增强粉体活性,促进低温活化烧结。该粉体在1100℃的低温下即可烧结成瓷;在1200℃烧结3h,陶瓷体致密度达到最大,约7.79g/cm^3,且晶粒尺寸相近,分布均匀。 相似文献
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The 0.5(BiGd0.05Fe0.95O3)-0.5(PbZrO3) composite was synthesized by means of a high temperature solid-state reaction technique using high purity ingredients. Preliminary X-ray structural analysis confirms the formation of the composite. The dielectric constant and loss tangent have been studied. The impedance parameters have been measured using an impedance analyzer in a wide range of frequency (102–106 Hz) at different temperatures. The Nyquist plot suggests the contribution of bulk effect only and the bulk resistance decreases with a rise in temperature. Electrical impedance confirms the presence of grain effect and hopping mechanism in the electrical transport of the material. The dc conductivity increases with a rise of temperature. The frequency variation of ac conductivity shows that the compound obeys Jonscher’s universal power law and from Jonscher’s power law fit confirms the Small Polaron (SP) tunneling effect. Temperature dependence of dc and ac conductivity indicates that electrical conduction in the material is a thermally activated process. 相似文献