Phase composition determination in HTSC materials by the method modulated microwave absorption

Method for determining phase composition of HTSC materials using the effect of modulated microwave absorption (MMA) in wear magnetic fields is suggested. Crystal YxNdyBa2Cu3-zAlzO6.9, where x = 0.65, y = 0.30, z - 0.2 was chosen as object under investigation. Temperature measurements were conducted in 3-300 K range. Temperature dependence of MMA signal value is presented. Four regions with Tc characteristic temperature, assigned to each one, can be distinguished on it. It is shown that high sensitivity (sample mass is less, than 0.01 mg) of MMA method enables to use it in combination with X-ray phase analysis for determination of phase composition of HTSC materials