E. Yu. Anikina

Calorimetric investigation of the hydrogen interaction with Ti0.9Zr0.1Mn1.1V0.1

Abstract The interaction of hydrogen with Ti 0.9 Zr 0.1 Mn 1.1 V 0.1 compound was studied by means of calorimetric and P – C isotherm methods. The obtained results allow to propose the existence of two hydride phases in the Ti 0.9 Zr 0.1 Mn 1.1 V 0.1 –H 2 system in the temperature range 72–116°C.

Interaction of hydrogen with the intermetallic compound Nd 2 Fe 17 studied by calorimetry

Interaction of hydrogen with the intermetallic compound Nd2Fe17 has been studied for the first time by calorimetry using a differential heat conduction calorimeter coupled to a Sieverts apparatus. Hydrogen absorption and desorption reactions were run at 200°C, and two types of data were obtained: p–C–T and ΔH–C–T (where p is the equilibrium hydrogen pressure, C = H/Nd2Fe17, ΔH is the reaction enthalpy, and T is the measurement temperature). The p–C–T curves obtained for the hydrogen absorption and desorption processes have no plateau or two-phase region, in contrast to what is characteristic of the formation of a hydride phase. At the same time, the ΔH(C) curves have a few portions where the enthalpy of reaction between hydrogen and the intermetallic compound remains constant: 0 < C < 2.0, with ΔHabs =–85.05 ± 0.65 kJ/mol H2; 2.0 < C < 2.7, with ΔHabs =–80.64 ± 1.00 kJ/mol H2; and 1.9 < C < 2.7, with ΔHdes = 76.48 ± 0.85 kJ/mol H2. The data obtained in this study suggest that positions 9e and 18g in the intermetallic compound are occupied by hydrogen in a particular order.

Investigation of hydrogen interaction with magnetic materials of Nd–Fe–B type by calorimetry method

The interaction of hydrogen with the Nd–Fe–B system is studied via calorimetry with use of a Tian–Calvet differential calorimeter and reconstruction of the pressure–composition isotherms (P–C–T, where Р is the equilibrium pressure of hydrogen, С = H/Nd2Fe14B, and T is the reaction temperature). No hybrid phase coexistence is found on the P–C hydrogen sorption/desorption isotherms or on plots of the dependence of the enthalpy on the hydrogen concentration in the metallic matrix. Nevertheless, several segments with constant enthalpy values can be distinguished in the reaction enthalpy on the hydrogen content plot.

Calorimetric Study of the Hydrogen Interaction with Ce6Ni1.67Si3

In the present work at the first time the hydrogen interaction with Ce6Ni1.67Si3 at pressure up to 45 atm and temperature 51˚C has been investigated by means of the calorimetric method. The ΔHabs. – C dependence (ΔHabs. –the partial molar enthalpy of the reaction of the hydrogen interaction with IMC, C – hydrogen concentration, C=H/IMC) was obtained.

Peculiarities of Hydrogen Interaction with Intermetallic Compounds Ab2

In the present work we compare the thermodynamic functions of the hydrogen desorption from ZrMn2-H, ZrMn2.7-H and Ti0.9Zr0.1Mn1..3V0.5-H systems, which were calculated on the base of data obtained from the study of these systems by means of P-C measurements (C=H/AB2) and the calorimetric method.