Materials Research Bulletin, Vol.32, No.5, 595-601, 1997
Ferromagnetism and Thermoelectric-Power of La1.5Ca1.5Mn2O7
We report on the preparation, X-ray diffraction, ac susceptibility, de magnetization and thermoelectric power (TEP) of La1.5Ca1.5Mn2O7. The compound has a tetragonal structure with lattice parameters a = 3.886(1) Angstrom and c = 19.34(1) Angstrom. Magnetic measurements reveal a ferromagnetic transition at around T-c = 215 K. TEP measurements indicate hole conductivity and has a maximum at T-c indicating an insulator to metal transition. Some possible reasons for the recently reported observation of T-c being far above the maximum of resistivity are pointed out.