ESR and magnetic susceptibility of Nd:YAG crystals

The ESR was studied in the 8-mm range. An upper limit has been established on the concentration of Nd³⁺ ions in octahedral sites of the crystal structure of Nd:YAG samples grown by the method of horizontal directed crystallization: no more than 5–7% of the total concentration of neodymium in dodechahedral lattice sites. The temperature dependence, over the range 5–300 K, of the magnetic susceptibility of Nd:YAG crystals grown by horizontal directed crystallization has been measured for the first time. The experimental results agree well with the predictions of a theory based on the assumption that the neodymium ions occupy only c lattice sites. The concentration of neodymium ions in these crystals has been determined. The diamagnetic component of the magnetic susceptibility has been evaluated.