On magnetic field effect on low-temperature impedance of HTSC yttrium ceramics in region of decimetric waves

Consideration is given to results of studying the effect of external magnetic field H in helium temperature range in the fields of f≅5·108 Hg frequency on high-frequency properties (that is, the real part of surface resistance rs) of yttrium ceramics. Surface resistance of HTSC YBa2Cu3O6+x ceramics for HF field with 70 cm wave length was studied by the method of detecting unloaded Q-factor of coaxial short-circuited resonator, made of examined material. It was established that at T=4.2 K rs changed lineaarly with H, excluding the region of fields, less than Hc1, where the dependence was quadratic. Value rs at T=4.2 K was equal to 0.020 hm, and at T=300 K - 0.70 hm. This correlated with the concept about the presence of ferroelectric giant absorption of HF field power