Correlation between vacancy defects and magnetic properties of the GdMn1-xZnxO3 multiferroic ceramics studied by positron annihilation

Abstract The GdMn1-xZnxO3 multiferroic ceramics were synthesized using the solid state reaction method, and the effects of Zn doping on the microstructure and magnetic properties of these ceramics were investigated. All of the samples formed single phase structure, and no structural transition occurred in the entire doping range. The SEM images showed that Zn doping prompted grain growth, and the high doping samples (x = 0.15 and 0.20) exhibited denser microstructure and lager, more well-connected grains. The Positron annihilation results revealed that the vacancy concentration first increased and then decreased with the increase in the Zn content; Zn doping does not change the defect species. Zn doping could obviously modulate the long-range order of Gd moments, transition temperature, and magnetization of the GdMn1-xZnxO3. The interplay between the microstructure and properties suggests that vacancy-type defects concentration is one of the most important factors that can tailor the magnetization of GdMn1-xZnxO3 ceramics.