Growth and Variable Temperature Hall Effect Study of SrPb₃Br₈ Crystal with Low Phonon Energy

Transparent and homogeneous SrPb3Br8 single crystals with the size of o25 mm x 50 mm are grown by the modified vertical Bridgman method. X-ray diffraction results reveal that the middle part of the crystal is pure in chemical compositions, while the tip part contains low content of Sr(PbBr3)(2)(H2O)(5). X-ray photoelectron spectroscopy analysis points out the absorption to C, O-containing substances of the pristine surfaces of SrPb3Br8 wafers. The Raman results prove the low phonon energy of the SrPb3Br8 (116 cm(-1)). Transmission spectra demonstrate its wide transparent range (0.37-25 mu m) and high transmittance in the mid-infrared range except for several absorption lines. Moreover, Hall measurements show that the SrPb3Br8 sample is n-type conductive at 110-300 K, and the Hall coefficient R-H, resistivity rho and mobility mu(H) decrease as temperature increases while the carrier concentration n has an opposite trend. The conduction mechanism and scattering mechanism of SrPb3Br8 crystal at different temperatures has been studied by analyzing ln(|R-H|)-T-1, n-T and mu(H)-T curves, and the dominant donor defect ionization energy E-D is calculated to be 0.077 eV.