Standard thermodynamic data for Rhodochrosite from equilibrium decomposition curve

Hydrothermal equilibrium decomposition curve for MnCO3 half arrow pointing right over half arrow pointing left MnO + CO2 in the total CO2 pressure range of 100-1700 bars and temperature range of 500-800-degrees-C was studied. The standard thermodynamic data obtained are: DELTA-H(f)0 = -894.382 +/- 0.74 kJ/mol and DELTA-G(f)0 = -822.170 +/- 0.74 kJ/mol. These values are more negative than the reported calorimetric data

HIGH TEMPERATURE SUPERCONDUCTIVITY IN Bi-Sm-Sr-Ca-Cu-O

X-ray diffraction, resistivity and magnetic susceptibility for BiSrCaCuO (2224) system and 10 % Sm substituted for Bi in (2223) system are reported. The high temperature transition at 110 K disappears when Sm is substituted while there is no major change in the lattice parameters. The possible role of Bi-O planes in the superconducting mechanism in this system is indicated

XDC AND MAGNETIC MÖSSBAUER SPECTRA OF YBa2 (Cu1-xFex)3 O7-δ

We find the paramagnetic Mössbauer spectra of YBa2 (CuxFe1-x)3 O7-δ can be fitted using symmetric doublets, iron is in high spin Fe3+ state in the oxide, and the present study provides further support to the presence of spin relaxation effects at low temperatures