High frequency ESR measurements of thiospinel CuCrZrS4

Thiospinel CuCrZrS₄ has been studied by high frequency ESR using millimeter wave vector network analyzer (MVNA, ABmm). A Lorentzian absorption line in ESR spectrum is observed at high temperatures. The estimated g-value is 1.98 at 198 K. This value well agrees with the g value Cr³⁺ free ion. With decreasing the temperature, the absorption at high temperatures splits into two absorptions below 100 K. While an absorption shifts to higher field, another absorption slightly shifts to lower field with decreasing the temperature. Resonance fields of both absorptions increase with increasing frequency at 4 K linearly. A possible model is discussed on the basis of the coexistent state of ferromagnetism and paramagnetism.