Electrodeposition of Transition Metal Alloy Films for Magnetic Thermometry

As part of an effort to develop methodology for magnetism-based thermometry, the present work seeks to develop materials and structures with temperature-dependent magnetic properties providing optimal sensitivity near room temperature, leveraging previous work which demonstrated compositional control of alloy films by varying the deposition potential. We will discuss deposition and characterization of these films with an emphasis on factors affecting their temperature-dependent magnetic properties, namely the effects of deposition potential and the presence of boric acid. A series of electrodeposited platinum nickel alloy films was characterized by superconducting quantum interference device vibrating sample magnetometry (SQUID VSM), and it was found that films deposited at more reducing potentials (those with higher nickel content) had predominantly ferromagnetic behavior, while films deposited at more positive potentials showed behavior with ferromagnetic and paramagnetic contributions. Depositions at more reducing potentials in the presence of boric acid proceeded with lower Coulombic efficiency and resulted in films with higher oxygen content and diminished magnetization relative to depositions in the absence of boric acid.