In this work the magnetic properties of CuxNi1-x alloy films of arbitrary composition has been studied. Our films were grown directly onto (111) n-type silicon using electrodeposition technique. Electrodeposition is an inexpensive, versatile and interesting tool for fabricating and characterizing nanostructures at room temperature such as alloys, nanowires and multilayers thin films. In this technique two conducting electrodes are placed in an electrolyte containing ions of metals to be deposited. We used an electrochemical bath containing 0.2mol NiSo4 and 0.02mol CuSo4 to prepare magnetic and non-magnetic NiCu alloys. In order to make a good ohmic contact, prior to electrodeposition the back side of Si substrate was painted by GaIn. Ni or Cu atoms then were deposited onto Si substrate by switching the applied potential between -1.5 and -0.4volt respectively. The nominal Cu thickness was kept constant at 4Å while the Ni nominal thickness was varied between 6 and 36Å (the value of x was changed between 0 and 0.5). If the individual layer thicknesses in an electrodeposited metal/metal multilayer are reduced, eventually the layers will become discontinuous. At this point, sequential electrodeposition of two metals will give a heterogeneous alloy, rather than a multilayer. The alloy may be made less heterogeneous by reducing the coverage of each metal still further. This is actually quite a useful way of making an alloy, because the composition may be changed during growth simply by changing the ratio of the amounts of each metal deposited per cycle.
An Alternating Gradient Force Magnetometry (AGFM) was used to prepare hysteresis loops of CuxNi1-x thin films. Room temperature magnetization normalized to the value measured for a pure Ni film, has been figured out for a series of films with the same total thickness (1µm) consisting different ratio of Cu and Ni.
Good control over the average composition of a CuxNi1-x alloy film has been achieved by using Energy-Dispersive X-Ray Spectroscopy (EDAX). A good agreement was found between the nominal and measured composition of the films consisting of different ratio of Cu and Ni.
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