Microwave dielectric property measurements of LaSrGaO4 single crystals having possible HTSC substrate applications

Cavity perturbation (CP) and Hakki-Coleman post-resonance (PR) methods were used for measuring the dielectric constant (ε′) and the tangent loss (tan δ) on single-crystal LaSrGaO4. These values, especially tan δ, are different from the earlier published data on LaSrGaO4 single crystals measured at room temperature and microwave frequencies of − 18 GHz. After annealing in an oxygen atmosphere, an increase in tan δ value was observed in the near-congruent LaSrGaO4 sample indicating the effect of a disordered structure in the crystal.