Ti-Substituted BaFe12O19 Single Crystal Growth and Characterization

详细信息    查看全文

• 作者：Denis A. Vinnik ; Dmitry A. Zherebtsov ; Lubov S. Mashkovtseva ; Sandra Nemrava ; Nikolai S. Perov ; Anna S. Semisalova ; Igor V. Krivtsov ; Ludmila I. Isaenko ; Gennady G. Mikhailov ; Rainer Niewa
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：November 5, 2014
• 年：2014
• 卷：14
• 期：11
• 页码：5834-5839
• 全文大小：339K
• ISSN：1528-7505

文摘

Ti-substituted barium hexaferrite BaFe₁₂O₁₉ single crystals BaFe_12鈥?i>xTi_xO₁₉ with x up to 1.3 and sizes 2鈥? mm were grown by spontaneous crystallization from molten sodium carbonate flux. The distribution of Ti on different crystallographic sites was determined from single crystal X-ray diffraction data. For low Ti contents up to x = 0.8 the unit cell expands; on further increase of the Ti amount the unit cell starts to shrink. This behavior for low Ti contents is most likely due to a reduction of Fe³⁺ to Fe²⁺ for charge balance. At higher Ti concentrations, supposedly vacancies in the transition metal substructure are formed. An increasing Ti concentration results in a monotonous reduction of the Curie temperature from 452 to 251 掳C and the saturation magnetization at room temperature from 64.8 to 24.8 emu/g for powder samples and from 70.0 to 60.1 emu/g for single crystals (for x up to 0.78).