Non-linear dielectric dispersion in PMN relaxor system
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文摘
In PbMg1/3Nb2/3O3 (PMN) single crystals the first ?1* and the third harmonic complex dielectric constant ?3* were measured along the 
001
and 111 axes as a function of frequency and temperature in a small electric field. In the temperature interval between 270 and 220 K the first ?1* and the third harmonic complex dielectric constant ?3*, and the dielectric non-linearity β=?3/?14?03 show prominent dielectric dispersion. It is also shown that the dielectric non-linearity β shows a crossover from a decreasing paraelectric-like to a rapidly increasing glass-like temperature behaviour which was predicted by the spherical random bond random field model for relaxors.
001 and 111 axes as a function of frequency and temperature in a small electric field. In the temperature interval between 270 and 220 K the first ?1* and the third harmonic complex dielectric constant ?3*, and the dielectric non-linearity β=?3/?14?03 show prominent dielectric dispersion. It is also shown that the dielectric non-linearity β shows a crossover from a decreasing paraelectric-like to a rapidly increasing glass-like temperature behaviour which was predicted by the spherical random bond random field model for relaxors.