Control mechanism of iron speciation on pyroelectricity of tourmaline containing Fe

Abstract

Although pyroelectricity of tourmaline was studied by previous researchers, the influence mechanism of Fe on pyroelectricity was still unclear. In the study, the valence state and occupation of Fe were determined by Mössbauer spectrometer, and as per the data from single-crystal X-ray diffraction, the distortion parameters and dipole moments of various polyhedrons in tourmaline were calculated, and the pyroelectricity was consistent with the intrinsic electric dipole moment. According to the results, the relationship among iron speciation, structural polyhedron, intrinsic electric dipole moment and pyroelectricity was investigated to discuss the influence mechanism of Fe on pyroelectricity of tourmaline. The T-GX sample (tourmaline sample collected from Hebei province, China) with high Fe content was exposed to gamma irradiation to induce a change of Fe speciation, making the tourmaline structure changed in favor of the intrinsic electric dipole moment, so as to improve the pyroelectricity of tourmaline. It was of great significance for the controllable improvement of mineral properties.