Application of EPR Spectroscopy for Investigation of Antisite Defectsin Yttrium-Aluminum Garnet

Paramagnetic Ce3+, Tb3+ and Ho3+ centers in the yttrium position in yttrium aluminum garnet (YAG) crystals investigated by the EPR spectroscopy. Along with the main EPR signals of Ce3+ and non-Kramers Tb3+ ions located in a regular environment a number of new centers with less lines intensity with different g-factors and zero-field splitting observed. The number of lines and the symmetry of these centers indicate that they belong to cerium and terbium ions, near which there are YAl antisite defects (Y3+ in octahedral positions of Al3+) or AlY (Al3+ in dodecahedral positions of Y3+). In addition to the main EPR signals of non-Kramers Ho3+ ions located in Y3+, a number of less intense lines with different parameters also attributed to antisite defects.