The influence of the structural defects on the physical properties of Er3Fe5O12 ferrite-garnet

It has been shown that structural defects can play a dominant role in the formation of the physical properties of ceramics. This paper presents the results of studying the physical properties of Er3Fe5O12 (ErIG) powders and ceramics, containing the structural defects of various types. The formation of the structural defects in ErIG was achieved by the mechanical activation of pre-synthesized powders using Bridgman anvils, to which fixed shear strain and uniaxial pressures of various magnitudes were applied in the range of 40–320 MPa. The lower anvil rotated at the speed of 3 revolutions per hour (rph). The structural parameters of the mechanically activated powders and ceramics sintered from them were studied at room temperature by the X-ray method. The band gap was determined by the optical spectroscopy, the magnetic properties were estimated from the hysteresis loops and the dielectric properties and heat capacity were studied in the high-temperature range. It has been established that mechanical activation leads to a significant smearing of antiferrimagnetic transition and to a shift in the phase transition temperature to the low-temperature region.