Preparation, Microstructure And Electromagnetic Properties Of The Transition Metal Dichalcogenide A_xTS₂（T=Ti,Zr）

Transition metal dichalcogenide is one of the typical layered material. It is regarded as apromising electrode material andsuperior lubrication material.LixTiS2(0≤x≤1) sampleswereprepared by a novel route at600oC in sealed tube using TiS2, Li2S and titanium powders, andthese compounds ATX2could also facile synthetized according to this novel route, such as,LixZrS2, KxTiSe2et al.Samples was charactered with X-ray diffraction(XRD), energydispersive X-Ray spectroscopy(EDX), scanning electronic microscope(SEM), transmissionelectron microscope(TEM), magnetic property measurement system(MPMS), differentialthermal analysis methods(DTA).The temperature dependence of electrical resistivity wasmeasured using the four probe method in the temperature range5K-300K.And3Rstructurerefinement was performed in FullProf program using a Rietveld method.In binary compounds, TiS2shown a semimetallic and paramagnetic behavior, butZrS2shown a metallic and paramagnetic behavior. In Ti1+xS2(0≤x≤0.5), there was asolid solubility limit while x=0.3. And all the sample of Ti1+xS2(0≤x≤0.5) shown a metallicand paramagnetic behavior. With the increasing titanium, effective Bohr magneton derivedfrom Ti3+and resistivity gradually decreased.A sketch structural phase diagram of LixTiS2with temperature and composition x wasobtained. We found that1T structure was a low temperature phase and the3R polytype was ahigh temperature phase. The higher of lithium content was conducive to develop3R structure.It was systematically researched to the crystal structure and the properties of electricaland magnetism a series of samples LixTiS2with x spanning the entire range of0≤x≤1. In1T-LixTiS2, the lattice parameter,“a, c and V”, gradually increased with the increasing lithium.In3R-LixTiS2, the lattice parameter “a and V” gradually increased with the increasing lithium,but cgradually decreased. A solid solution modelof3R phasewas build, and the structurerefinement was performed in FullProf program using a Rietveld method. The result ofRietveld refinement shown that some atoms of Li appeared in the site of Ti with occupancy0.237and some atoms of Ti appeared in the site of Li and with occupancy0.136,and the lattice parameter was a=3.498(3), c=18.248(2).There was a transformation fromsemimetallic to metallic in1T-LixTiS2with the content of lithium increasing, and theresistivity decreased. All samples LixTiS2show paramagnetic behavior. With the increasinglithium, effective Bohr magneton and resistivity gradually decreased. The result of decreasingresistivity agreed well with the sample ρ-T curves. Possibly, it isn’t a good method to developlocalized electron by doping alkali metal inTiS2.Preparation and the electrical property of AlxTiS2(0≤x≤0.1) and MgxTiS2(0≤x≤0.1) wasinvestigated, and these materials shown the metallic behavior. The preparation of Y0.3TiS2,La0.3TiS2was also investigated, and phase separation maybe arise with the higher dopingmetal.