@article{oai:nagoya.repo.nii.ac.jp:00030849,
 author = {Naito, Keiji and Inaba, Hideaki and Matsui, Tsuneo},
 issue = {1},
 journal = {Memoirs of the Faculty of Engineering, Nagoya University},
 month = {Oct},
 note = {A review on the calorimetric studies of nuclear materials at high temperatures carried out recently in our laboratory is given. The apparatus used in this study are as follows ; an adiabatic scanning calorimeter, a direct heating pulse calorimeter, an apparatus for measuring thermal conductivity by means of a scanning temperature method, a twin microcalorimeter of Tian-Calvet type, a time-of-flight mass-spectrometer with a Knudsen-cell, etc. Heat capacities of U4O9-y, U3O8-z, MnxFe3-xO4, CrxFe3-xO4, VOx, NbO2 and doped NbO2 with various compositions have been measured and the mechanisms of phase transitions are discussed from the entropy changes due to the transitions as a function of composition. Thermal conductivities of U4O9-y, U3O8-z and MnxFe3-xO4 have been measured and discussed as a function of composition. Heats of formation of NbOx with various x have been measured and the stability of the compounds is discussed in comparison with VOx and Ta2O5. Vaporization of the niobium-oxygen system, Nb2O5-x, NbO2±x, NbO1±x, and Nb-O solid solution phases has been measured with emphasis on their nonstoichiometry. The congruently vaporizing phase in the niobium-oxygen system is determined to be NbO2. The enthalpy of ormationf and dissociation energy for NbO2(g) and NbO(g), enthalpy and entropy of fusion for NbO2(s) and Nb2O5(s) and the partial molar enthalpy and entropy of oxygen in solid phases are determined from the vapor pressure data. The defect structure of Nb-O solid solution and NbO2±x(s) is discussed from the partial molar enthalpy and entropy of oxygen and the phase diagram of the niobium-oxygen system at high temperatures is presented.},
 pages = {36--100},
 title = {A Calorimetric study on nuclear reactor materials at high temperatures},
 volume = {35},
 year = {1983}
}