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A porous nickel support was successfully prepared by uniaxial compression of nickel powders. Microstructures and mechanical properties of Nb(40)Ti(30)Ni(30) membranes fabricated by magnetron sputtering were investigated. Deposited and annealed Nb(40)Ti(30)Ni(30) membranes consisted of amorphous and crystalline phases, respectively. Higher base temperature was shown to increase the hardness and elastic modulus of the Nb(40)Ti(30)Ni(30) membrane, Pd/Nb(40)Ti(30)Ni(30)/Pd/porous nickel support composite membranes were then fabricated using a multilayer magnetron sputtering method. The hydrogen permeability of the composite membranes with amorphous and crystallized Nb(40)Ti(30)Ni(30) metal layer was measured and compared with that of self-supported Nb(40)Ti(30)Ni(30) and Pd alloys. Solid-state diffusion was shown to be the rate-controlling factor when the thickness of the Nb(40)Ti(30)Ni(30) layer was about 12 pm or greater, while other factors were in effect for thinner layers (such as 6 pm). The Pd/Nb(40)Ti(30)Ni(30)/Pd/porous nickel support composite membrane exhibited excellent permeation capability and satisfactory mechanical properties. It is a promising new permeation membrane that could replace Pd and PdAg alloys for hydrogen separation and purification. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.