Synthesis and Characterization of Metal–Oxide Composite Materials for Permanent Magnetic Applications

Aleksey Volodchenkov, Ph.D Student
Mechanical Engineering, University of California Riverside

State of the art magnets depend heavily on the use of rare-earth materials and cost 10 to 20 times more than other magnets such as ferrite magnets, per weight.  In addition, the global supply  of  crucial  rare-earth  elements  is  uncertain,  causing  a  real  threat  to  the  magnetic industry.  Effective  use  of  exchange  coupling  between  hard  and  soft  magnetic  materials could  decrease  reliance  on  rare-earth  based  magnetic  materials  and  lower  the  cost  of  high performance permanent magnets. Despite the promise, engineering a composite permanent magnetic material with enhanced magnetic properties as a result of exchange coupling has been  an  elusive  goal.  Research  described  in  this  thesis  centers  on  the  synthesis  and characterization  of  metal-oxide  3D  bulk  composite  materials  for  permanent  magnetic applications.  Samples  were  densified  from  powders  using  the  Current  Activated  Pressure Assisted  Densification  (CAPAD)  apparatus.  A  range  of  samples  with  densities  as  high  as 97% relative density have been synthesized in relatively short times (~10 minutes). Samples have been shown through X-ray diffraction (XRD) to contain desired composition, and are indeed hard and soft magnetic composites. The applied pressure has been shown to play a significant  role  in  increasing  density  and  in  turn  improving  the  magnetic  properties. Enhanced magnetic saturation of the composite material, as compared to the mass dominant hard phase has been observed.

Aleksey relocated from Moscow to Los Angeles in 1998. He received two BS degrees (Aerospace Engineering and Material Science Engineering ) in 2010 from UC   Irvine and was awarded an MS degree in Mechanical Engineering in summer 2012 from UC Riverside.  Aleksey is currently a Ph.D student for Dr. Javier Garay’s lab.