The Growth And Performance Test Of KCl_1-xBr_x Crystal

In this paper,the crystal growth of KCl_1-xBr_x（x=0.0,0.2,0.4,0.5,0.6,0.8,1.0）were systematically studied,and the properties of KCl_1-xBr_x crystals were tested and analyzed.The raw materials of different factories were tested by X ray diffraction and infrared spectrum,the raw materials of KCl and KBr were selected.the polycrystalline material of KCl_1-xBr_x was prepared by proportioning,weighing,acidification,filtration,evaporation crystallization,mixing and compression.Pulling speed was 1-2 mm/h,rotation speed was6-8 r/min,circulating water temperature was 28±1℃,the reasonable temperature field was designed.the KCl_1-xBr_x crystal with intact shape and no macroscopic defect was grown in the atmosphere by the Czochralski method.The influence of different process conditions on the crystal quality was studied.The KCl_1-xBr_x crystal were cut and polished into 12×8×2-3mm crystal element,which were tested by X-ray diffraction,EDX spectroscopy,absorption spectrum.the results showed that the lattice constants of KCl_1-xBr_x crystal accorded with Vegard law,the difference between the x value of the component and the theoretical value was small,the component design of polycrystalline material was reasonable and there was a low absorption.Thermal parameters（Debye-Waller factor,Debye temperature and Debye frequency）of KCl_1-xBr_x crystal were calculated according to X ray diffraction intensity data.The influence of x at the same temperature on the electrical properties of KCl_1-xBr_x crystal was studied.It was found that at the same temperature,the KCl_0.5Br_0.5 crystal had higherσ_dc,ε_r,tanδandσ_acc at x=0.5.the Vickers hardness tester was used to test the Vickers hardness（H_v）of KCl_1-xBr_x crystals at room temperature,the results showed that the H_v of KCl_0.5Br_0.5 crystal was the largest at x=0.5.