Study On The Preparation Magnetic And Dielectic Properties Of Oxide Materials

In recent years, low dimensional magnetic materials are the research frontiers of materials science and condensed matter physics applications, which own important theoretical research value and potential application value. Dielectric materials are the kinds of important functional materials, own high dielectric constant characteristic, used in produce capacitor, storage, filter etc. Therefore, for new type of low dimensional magnetic materials with high dielectric materials have become hot research field in current chemistry and materials science. Our purpose is the study of magnetic and electrical properties of low dimensional magnetic materials. In 32 kinds of point groups of crystal, 21 kinds of point groups own center symmetry, in the 21 kinds of point groups, only 10 of them have the asymmetric polar axis, which have the spontaneous polarization, all of them are 1(C1), 2(C2), m(Cs), mm2(C2v), 4(C4), 4mm(C4v), 3(C3), 3m(C3v), 6(C6), 6mm(C6v). This paper choose the 10 point groups of compounds which containing low dimensional magnetic chain, their pure phase were obtained through the traditional solid phase method. Focused on the magnetic properties and dielectric properties of these compounds. These thesis mainly research results and conclusions are as follows:(1) Through the solid phase method, synthesized with VO4 anionic groups as the basic structural unit of KBaCuV2O7 Cl two-dimensional magnetic chain compound. The results show that the compound KBaCuV2O7 Cl magnetic performance for paramagnetism. Then at low temperature on the dielectric properties was tested under different frequencies, found no phase change under low temperature, due to the synthesis of compound KBaCuV2O7 Cl temperature is low, for its dielectric properties at room temperature to look for other means of testing.(2) Through the solid phase method, synthesized with TaO4 anionic groups as the basic structural unit of KCuTa3O9 two-dimensional magnetic chain compound. The results show that the compound KCuTa3O9 macroscopic magnetic performance for antiferromagnetism. Then at low temperature on the dielectric properties was tested under different frequencies, found with lower temperature, the dielectric constant is gradually rise. The test shows that in the temperature range, the compound exhibits paraelectric behavior, without the ferroelectric phase transition.(3) Through the solid phase method, synthesized with BO3 anionic groups as the basic structural unit of Ln(Ln=La,Sm,Eu,Gd)Ba CuBO5 two-dimensional magnetic chain isostructural compound. The results show that the compound LaBaCuBO5 macroscopic magnetic performance for diamagnetism, compound EuBaCuBO5 macroscopic magnetic show the antiferromagnetism, compound GdBaCuBO5 macroscopic magnetic performance for paramagnetism, compound SmBaCuBO5 macroscopic magnetic performance for spin canting antiferromagnetism. To them on the room temperature on the dielectric properties was tested under different frequencies, find their dielectric loss is bigger, and over the measurement range, instrument already could not distinguish the real component. Beyond the range of the instrument, and gives a negative number. The energy consumption in the process of loss that is polarized.