On the interrelationship of porosity and structural defects in amorphous-crystalline nanopowders SiO2-doped Gd2O3 with their magnetic and luminescent properties

Abstract

The pulsed electron beam evaporation method (PEBE) was used to obtain mesoporous amorphous-crystalline pure and SiO2-doped Gd2O3 nanopowders (NPs). An HRTEM phase analysis showed the existence in nanopowder Gd2O3 of an amorphous, as well as three crystalline phases. The influence of silicon oxide doping on the textural, magnetic and luminescent properties of NPs Gd2O3@SiO2 was studied. The size and volume of the interparticle pores of NPs Gd2O3@SiO2 was dependant on the concentration of a dopant. The doping supported an increase in amorphicity and the growth of a concentration of different structural defects in NPs. Two different processes – annealing and doping, led to crystallinity degradation of the Gd2O3 matrix. The correlation of porosity concentration dependences, paramagnetic response, and the intensity of pulsed cathodoluminescence spectra in NPs Gd2O3@SiO2 was revealed. The dependence of the paramagnetic response Gd2O3 on the volume of interparticle mesopores in nonporous nanoparticles expands our understanding of the nature of diluted magnetic semiconductors.