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Ferrites Research and

Carbon Nanotube Production

Commercial Toroid
Commercial toroid
Toroid synthesized in our lab
Toroid synthesized in our lab
Carbon Nanotube
Carbon Nanotube grown on copper disk

Drs. Ramkumar and Bresser continued to do research on testing the structural integrity of ferrites for use as possible pressure sensors and producing carbon nanotubes (CNTs) by a chemical vapor deposition (CVD) technique.

We have successfully synthesized ferrite composite materials, (MnZn)xFe3-xO4 using metal oxides and prepared toroids using these ferrite materials. These toroids change their inductance (magneto-mechanical properties) when external pressure is applied. Various sample preparation methods were tested to increase structural integrity of these toroids. Our recent research reveals that toroids prepared in our laboratory have developed grain structure that is very close to commercially manufacture toroids. This structural integrity is very important for potential pressure sensor applications. Two students, Jared Carr and Robert Theis had worked on this project during summer 2015 and were supported by UR-STEM 2015. Their results were described in a poster “Improving Structural Integrity of Ferrite Magnet Toroids for Pressure Sensor Applications” for the Bullen Summer Research Celebration in August 2015.

We have also produced high-yield CNTs using CVD technique on copper disks coated with different metal particles as catalysts. Our recent graduate Jonathan Wright had worked on this project as well as students from Advanced Physics Laboratory. Currently two students, Carlos Butler and Thomas Haines, are working to grow CNTs in the presence of electric field. The bottom image shows CNTs grown on copper disk with cobalt as the catalyst.

In order to exploit and fine-tune their magneto-mechanical properties for potential pressure sensor application, we plan to incorporate CNTs into the ferrite materials and investigate their effect on the mechanical strength of toroids made of these ferrite materials.

During the summer of 2014, two students: Meredith Barone and Thomas Haines had worked on the ferrite materials project. The results of their UR-STEM project (Summer 2014) were described in their poster entitled “Enhancing the Structural Integrity of Ferrite Magnets for Magneto-Elastic Pressure Applications by Improving Various Sample Preparation Methods” for the Posters-at-the-Capitol in Frankfort, KY, February 19, 2015.

Published Papers in 2014

“Rigidity transitions in glasses driven by changes in network dimensionality and structural groupings, EPL 108, 5600 (2014), K. Vignarooban, P. Boolchand, M. Micoulaut, M. Malki, W.J. Bresser.