engleski

Electron spin resonance and relaxation studies of double-layered manganites

Electronic properties of La2-2xSr1+2xMn2O7 (x=0.4 and 0.5) single crystals are studied by spin resonance (ESR) and spin-lattice relaxation time measurements. Spin susceptibility chi(T) determined from the ESR signal intensity and makroscopically measured static-susceptibility data are in good agreement, thus ESR detect all spin species in the system. In both compounds, the ESR spectra contain a single, nearly isotropic Lorentzian line associated with the exchange coupled Mn+3 and Mn+4 ions. For the x=0.5 compound, the fingerprints of charge ordering (CO) transition at Tco=226K are detected. In addition, strongly anisotropic ferromagnetic resonance spectra are found in both materials, suggesting the presence of extrinsic ferromagnetic phase.

ESR ; susceptibility ; ferromagnetic resonance ; charge-ordering

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