(Georgia Institute of Technology, 2010-05-12)
Vavra, Kevin Christopher
It is known that copper and nickel deposited at specific ratios results in alloys that exhibit magnetic properties. The objective of our study is to prepare the Cu-Ni alloys with different magnetic properties and investigate the resulting mechanical properties. To this end, thin alloy films were potentiostatically deposited on gold coated 10MHz piezoelectric quartz crystal microbalances (QCM). Selected deposition potentials varying from -850mV to -1300mV yielded alloys containing varying NixCuy compositions. Additional studies used alternating pulses of applied voltage that yielded definable pulse widths and heights or an alternate bath that allowed for further investigation on the presence of counterions. Magnetic property characterizations of these depositions were performed using the magnetic quartz crystal microbalance (MQCM) instrument. Preliminary results have demonstrated that the resonant frequency does not change during the application of a magnetic field to homogenous layers of paramagnetic or ferromagnetic materials. However, dispersions of Ni in a non-magnetic Cu matrix produced changes in resonant frequency. Such nickel dispersions can be electrochemically fabrication thereby affecting the magnetically induced QCM resonance shift and admittance magnitude.