ESR of Copper Doped Ammonium Tartrate

Abstract

The results of ESR studies of Cu²⁺ ion doped in Ammonium Tartrate single crystal at room temperature are reported. Copper enters the lattice substitutionally and is trapped at two magnetically inequivalent sites. The observed spectra are fitted to a spin-Hamiltonian of rhombic symmetry with the following values of the spin-Hamiltonian parameters. Cu²⁺(I): g_x=2.0469±0.002, g_y=2.1522±0.002, g_z=2.4489±0.002 and A_x=(56±2)10⁻⁴ cm⁻¹, A_y=(66±2)10⁻⁴ cm⁻¹, A_z=(79±2)10⁻⁴ cm⁻¹. Cu²⁺(II): g_x=2.0292±0.002, g_y=2.1477±0.002, g_z=2.4186±0.002 and A_x=(36±2)10⁻⁴ cm⁻¹, A_y=(63±2)10⁻⁴ cm⁻¹, A_z=(73±2)10⁻⁴ cm⁻¹. The ground state wave function of the Cu²⁺ ion in ammonium tartrate is evaluated. It is found that the ground state is predominantly |x²−y²⟩.