A series of crystals with different doping concentrations of [NH_2(CH_3)_2]Mn_(1-x)Mg_x(HCOO)_3(0 ≤ x ≤ 0.5)were synthesized by hydrothermal method,and characterization analysis was made on the crystals by X ray powder diffraction, UV-Vis spectrum,Fourier transform infrared spectroscopy(FTIR),and thermogravimetry.The experimental results show that the obtained crystals are of good crystallization property,high transparency,and trigonal system with space group R-3c(167);the distortion of the Mn-O_6 octahedra...