The non-resonant microwave absorption (NRMA) measurements have been intensively performed for superconducting thin films of YBa 2 Cu 3 O y fabricated on MgO (100) substrates and powder samples of LaSrCuO systems. In order to complement the study, we also review the NRMA of BiSrCaCuO system. A particular attention has been paid to the following phenomena: (i) phases, (ii) effect of current, (iii) directional effect of applied magnetic field, (iv) hysteresis, (v) microwave power absorbed as a function of magnetic field, (vi) linewidth in the vicinity of T c , and (vii) modulation amplitude effect. A preliminary study on ( La 0.98 Dy 0.02)1.85 Sr 0.15 CuO 4 was also reported.

Several samples of K 3 C 60 have been made by the calcination of C 60 powder plus K flakes in evacuated quartz tubes at temperatures between 100°C and 700°C for 24 hours. The non-resonant microwave absorption (NRMA) measurements have been done below T c for these samples. From the linewidths and intensities of the NRMA signals, the superconducting properties (T c superconducting volume fraction and vortex size) have been studied as a function of the calcination temperature.

ESR measurements have been carried out on La 0.7 Ca 0.3 MnO 3. Distorted signals have been observed below about 255 K, but clear signals above ≃ 270 K . The temperature dependence of the low-temperature ESR linewidth nearly follows the magnetization (or susceptibility). The ESR intensity exhibits an anomalous increase at temperatures between about 200 K and 260 K with a peak at around 250 K; quite similar behavior to that of the resistivity, indicating a possible correlation between the resistivity and the ESR intensity. The temperature dependence of the ESR linewidth and intensity has been also studied above 300 K.

ESR measurements have been carried out for La 0.97 Ca 0.03 MnO 3 at temperatures from 4 K up to 760 K. below ≃243 K , two kinds of spectra, the high-field and low-field signals, are observed down to 96 and 4 K, respectively. They are assumed to be due to Mn 4+ and Mn 3+ ions, respectively. From the g-shifts of the high-field ( Mn 4+) signals, the magnetic interaction coefficient between Mn 4+ and Mn 3+ spins is estimated. Clear single ESR was observed above ≃255 K , and its linewidth and intensity are obtained as a function of temperature. The linewidth nearly follows exp (-550/T), and the intensity gradually deviates from Curie's law below ≃550 K , presumably due to the spin-cluster formation.

A number of pellets with nominal concentration ratio of Y:Ba:Cu =2:1:1 have been sintered in air at temperatures between 800°C and 1400°C for 1 min ~24 h. The heat-treated samples were quenched to room temperature and the crystal growth rates of Y 2 BaCuO y≃5 were measured using ESR of Cu 2+. Systematic data on the growth rates were taken as a function of heat-treatment temperature and period.