Uranium Monosulfide. The Ferromagnetic Transition. The Heat Capacity and Thermodynamic Properties from 1.5° to 350°K

The heat capacity of uranium monosulfide was measured from 1.5° to 22°K by an isothermal (isoperibol) method and from 6° to 350°K by an adiabatic technique. The ferromagnetic transition at 180.1°K has a characteristic lambda shape and associated magnetic ordering entropy and enthalpy increments of 1.62 ± 0.2 cal °K−1mole−1 and 231 ± 20 cal mole−1, respectively, over the temperature range 0° to 230°K. The correlation of the thermal data with magnetic studies is discussed. The heat capacity below 9°K is represented by Cp  =  5.588 × 10−3T + 2.627 × 10−4T3 / 2 + 6.752 × 10−5T3cal°K−1mole−1Cp=5.588×10−3T+2.627×10−4T3∕2+6.752×10−5T3cal°K−1mole−1, in which the successive terms represent conduction electronic, magnetic, and lattice contributions. Values of the entropy [S°], enthaply function [(H° − H°0) / T][(H°−H°0)∕T], and Gibbs‐energy function [(G° − H°0) / T][(G°−H°0)∕T] are 18.64 ± 0.005, 8.94 ± 0.002, and − 9.70 ± 0.02 cal °K−1 mole−1, respectively, at 298.15°K. The Gibbs energy of formation at 298.15°K is − 72.9 ± 3.5 kcal mole−1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70623/2/JCPSA6-48-1-155-1.pd

Heat capacity from 5 to 350 K and thermodynamic properties of cesium nitrate to 725 K

The low-temperature heat capacity (5 to 350 K) of CsNO3 was determined by adiabatic calorimetry. No anomalies were observed in this temperature region, the curve of heat capacity against temperature having the normal sigmoid shape. These measurements yielded the thermodynamic properties at 298.15 K: Cp[deg]=(96.47+/-0.19)J K- mol-; S[deg]=(153.95+/-0.31)J K- mol-; {H[deg](T) - H[deg](O)} =(20046+/-40)J mol-; {G[deg](T) - H[deg](O)}/T =(86.71+/-17)J K- mol-.These measurements have been combined with published high-temperature heat capacities to give the thermodynamic properties of CsNO3 to 725 K.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24563/1/0000844.pd

Thermodynamics of the Lanthanide Trifluorides. I. The Heat Capacity of Lanthanum Trifluoride, LaF₃ from 5 to 350°K and Enthalpies from 298 to 1477°K

The heat capacity of a sample of LaF3 was determined in the temperature range 5-350°K by aneroid adiabatic calorimetry and the enthalpy from 298.15 to 1477°K by drop calorimetry. The heat capacity at constant pressure C°p(298.15°K), the entropy S°(298.15°K), the enthalpy [H°(298.15°K)-H°(0)] and the Planck function -[G°(298.15°K)-H°(0)]/298.15°K; were found to be (90.29±0.09) J °K-1·mole-1, (106.98±0.11) J °K-1·mole-1, (16717±17) J mole-1, and (50.91±0.05) J °K -1·mole-1. The thermal functions from the present research were extended up to the melting temperature (1766°K) by combination with previously published results. The anomalously high heat capacity from about 1100 to 1766°K is discussed

Specific heat of apiezon T grease from 1 to 350[deg] K

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33364/1/0000762.pd

Dimanganese Phosphide, Mn₂P: Heat Capacity from 5 to 350 K, Magnetic Entropy, and Thermodynamic Functions to 1300 K

The heat capacity of a sample of Mn2P was determined in the temperature range 5 to 350 K by aneroid adiabatic calorimetry. A small peak in the heat capacity correlated with the antiferromagnetic ordering of the compound was found at (102.5 ± 0.5) K. The associated magnetic entropy was calculated to be (9.43 ± 0.52) J K-1 mol-1. The heat capacity at constant pressure Cp o(298,15 K), the entropy So(298.15 K), the enthalpy {Ho(298.15 K) - Ho(0)}, and the function {Go(298.15 K) - Ho(0)} 298.15 K were found to be (73.54 ± 0.22) J K-1 mol-1, (91.01 ± 0.27) J K-1 mol-1, (14037 ± 42) J mol-1, and -(43.93 ± 0.13) J K-1 mol-1, respectively. Values of these functions at selected temperatures up to 1300 K are presented in tabular form. The coefficient γ for the contribution of the conduction electrons to the heat capacity (γT) was found to be (23.7 ± 1.6) mJ K-2 mol-1

Heat Capacity and Thermodynamic Properties of Triuranium Silicide from 1 to 1203 K

The heat capacity of triuranium silicide, U3Si, has been measured from 1 to 350 K and its enthalpy determined from 298 to 1160 K. The coefficient γ for the heat capacity contribution of the conduction electrons (γT) is (39.3 ± 0.4) mJ K-2 mol-1. Thermodynamic functions are tabulated at selected temperatures between 1 and 1203 K. At 298.15 K, the values determined for the heat capacity Cp o, the entropy So, the enthalpy {Ho(298.15 K) - Ho(0)}, and the function {Go(298.15 K) - Ho(0)} 298.15K are (107.90 ± 0.43) J K-1 mol-1, (174.02 ± 0.70) J K-1 mol-1, (23297 ± 93) J mol-1, and -(95.88 ± 0.38) J K-1 mol-1, respectively. The standard Gibbs energy of formation ΔGf o(U3Si, c, 298.15 K) = -(105.6 ± 19.2) kJ mol-1 was derived