Alkali-lithium modification on rare-earth-neodymium-doped barium strontium sodium niobate ceramics for dielectric and pyroelectric properties

摘要

The influence of alkali-Li~+ modification on rare-earth Nd~(3+)-doped BSNN tungsten bronze system and its effect on phase formation, dielectric and pyroelectric properties is reported. The structure of Ba_(1.45)Sr_(2.4)Nd_(.01)Li_xNa_(2-x)Nb_(10)O_(30) ceramics is comprehensively studied in the range of x=0.0<=x<=1.0. X-ray diffraction studies indicated single orthorhombic {mm2) phase supported by tolerance factor and average electronegativity difference of BSNLNN compositions. The average particle size was maximum (406 A) at Lio.6. The dielectric properties are maximum (epsilon_(RT) = 649 and epsilon_(T_c) = 1254) at 1 kHz for Li_(0.6). The values of T_c for Li-modified and Nd-doped BSNN varied from 190 deg C to 202 deg C. The rho_(max) value in the order of 10~(10) OMEGA cm which is three orders of magnitude larger when compared with the rho_(RT). The value of rho_(max) is 1.05 X 10~(10) OMEGA cm observed at x = 0.2 of BSNLNN ceramics.