ELECTRON-SPIN-RESONANCE STUDY ON ND-0.7(SR0.3-XCAX)MNO3

Electron spin resonance (ESR) spectra of Nd-0.7(Sr0.3-xCax)MnO3, powde rs (0 less than or equal to x less than or equal to 0.3) have been mea sured over the range of temperature between 110 and 290 K. While for x = 0.2, 0.25 and 0.3 only one absorption line (Line I), corresponding to a g-value around 2, was observed while for x = 0 and 0.1 an additio nal line (Line II) was observed below the magnetic transition temperat ure. Based on the temperature dependent g-values and Delta H, we have assigned the ESR signal of Line I to the Mn4+ -ions, while that of Lin e II to the ferromagnetic resonance due to the ferromagnetic coupling between Mn4+ and Mn3+.