Abstract: The structure of Electroless Ni-Palloy has been studied by using DTA,XRDand EXAFSmethods,The P 10%(weight percentage ratio) Ni-Pcoating is a non-crystal alloy.The action between Ni and Pis a convalent bond applied force,The lengths of Ni Ni and Ni Pbonds are 0.25 nm and 0.28 nm.The P 10% Ni-Pcoating after heat treatment at 400℃ is a mixture of Ni₃Pand non-crystal Ni-P.The formation of nickel phosphonus likely structure is established by EXAFSand confirmed by experiments in contrast to DTAand XRDwhich does not provide more information.The extended X-ray absorption fine structure(EXAFS) spectrophotometry developed with the development of synchronous radiation light.It is very suitable for the studies of non-crystal alloy.The coordination environment of Ni and Pin Ni-Palloy coating has been measured by means of EXAFS.The degree of order in Ni-Palloy increases by the heat treatment.The loss of long-range order is even more pronounced with the increasing Pcontent in Ni-Pcoating.The local order around Ni in Ni-Palloy coating resembles that in Ni metal.The discription of structure may be useful for interpretation of the properties Ni-Pnon-crystal alloy coating from the view of molecular level.

Key words: Electroless plating Ni-P, EXAFS, XRD, DTA