Electron Paramagnetic Resonance of Gd3+ in Single Crystals of Various Rare-Earth Ethyl Sulfates at Room Temperature and at 77°K

Electron paramagnetic resonance studies of Gd³⁺ in single crystals of ${\mathrm{Ln(C}}_2{\mathrm{H}}_5{\mathrm{SO}}_4{)}_3\text{· 9}{\mathrm{H}}_2\mathrm{O}$ (where Ln³⁺ denotes La³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Yb³⁺, and Lu³⁺) have been carried out at X band at room temperature and at 77°K. The spin Hamiltonian parameters $b_2^0{\mathrm{,\hspace{0.17em}b}}_4^0,$ and $b_6^0$ and $g_{\Vert }$ have been evaluated at both temperatures for each host except terbium ethyl sulfate at 77°K. The absorption linewidths for each transition have been measured at both temperatures. The present results are compared with previous results. A principal conclusion is that the magnitude of $b_2^0$ for Gd³⁺ in the various rare‐earth ethyl sulfates is more nearly a linear function of the ionic radius of the trivalent host ion than of its atomic number.