The structure and magnetic properties of HoCu2 compound after hydrogenation were investigated. The results show that crystalline hydride Ho- Cu2Hx, lattice distorted hydrides and a mixture of the two hydrides can be o...The structure and magnetic properties of HoCu2 compound after hydrogenation were investigated. The results show that crystalline hydride Ho- Cu2Hx, lattice distorted hydrides and a mixture of the two hydrides can be obtained by hydrogenation. Ho- Cu2Hx remain the same structure as the matrix. Ho- Cu2H3.04 arrives the maximal hydrogen content, accompanied only by 2.27% lattice expansion,展开更多
The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu_2(CeCu_2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of ...The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu_2(CeCu_2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of HoCu_2 were a mixture of Cu, unknown hydride Ⅰ, and unknown hydride Ⅱ. Based on the PCT(pressure-concentration-temperature) curves under different reaction temperatures, the relationships among reaction temperature, equilibrium pressure, and maximum hydrogen absorption capacity were analyzed and discussed. The enthalpy change ΔH and entropy change ΔS as a result of the whole hydrogenation process were also calculated from the PCT curves. The magnetization and volumetric specific heat capacity of the hydride were also measured by SQUID magnetometer and PPMS, respectively.展开更多
文摘The structure and magnetic properties of HoCu2 compound after hydrogenation were investigated. The results show that crystalline hydride Ho- Cu2Hx, lattice distorted hydrides and a mixture of the two hydrides can be obtained by hydrogenation. Ho- Cu2Hx remain the same structure as the matrix. Ho- Cu2H3.04 arrives the maximal hydrogen content, accompanied only by 2.27% lattice expansion,
基金Project(51276154)supported by the National Natural Science Foundation of ChinaProject(2012010111014)supported by the University Doctoral Subject Special Foundation of China
文摘The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu_2(CeCu_2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of HoCu_2 were a mixture of Cu, unknown hydride Ⅰ, and unknown hydride Ⅱ. Based on the PCT(pressure-concentration-temperature) curves under different reaction temperatures, the relationships among reaction temperature, equilibrium pressure, and maximum hydrogen absorption capacity were analyzed and discussed. The enthalpy change ΔH and entropy change ΔS as a result of the whole hydrogenation process were also calculated from the PCT curves. The magnetization and volumetric specific heat capacity of the hydride were also measured by SQUID magnetometer and PPMS, respectively.
