Research Interests

Synthesis and chararacterization of uniform nano-dots and uniform nano-wire. Study ferromagnetic tunneling junctions (spintronics) and its fabrication as magnetic sensor. Growth of ferromagnetic materials, magnetic oxides, metallic thin films, and high temperature superconductors, by sputtering and other vacuum techniques. Study electrical and magnetic properties, and phase transitions of these materials by resistivity, electrical, ac susceptibility, magnetization measurements.

Recent Publications

“Numerical Calculation of Interaction between the Ferromagnetic dots and Vortices,” Bo Cheng, Tony Ragsdale, and W. J. Yeh, Inter. J. Modern Phys. B, 17, 3392 (2003).

“IV Characteristics of YBCO Thin Film with Ni dots,” W. J. Yeh, Bo Cheng, B. L. Justus, Physica C, 388, 344 (2003).    

“Regular Array of Magnetic Nano-Dots Prepared by Nanochannel Glass Replica masks,” Bo Cheng, Kun Yang, B. L. Justus, and W. J. Yeh, published in the MRS Proceedings: “Magnetic and Electronic Films Microstructure, Texture and Application to Data Storage,” edited by S.D. Harkness, et al. Vol. 721, E5.6 (2002)

"Variable Temperature SQUID Microscope," Bo Cheng and W. J. Yeh, Rev. Sci. Instru. 71, 1472 (2000).

"SQUID Microscope," Bo Cheng and W. J. Yeh, Inter. J. Modern Phys. B, 13, 3747 (2000).

"3D versus 2D Behavior in Ceramic Tl-2223 High-Tc Superconductors," W. J. Yeh and Z. Q. Yu, Physica C, 282-287, 2005 (1997).

"Vortex Dynamics and Vortex Melting in YBCO Thin Films Studied by SQUID," W. J. Yeh, L. K. Yu and Y. Zhang, Physica C, 282-287, 2351 (1997).

Scaling Behavior and 3D-2D Dimensional Crossover in Ceramic Tl High Temperature Superconductor," Z. Q. Yu and W. J. Yeh, Physica C, 273, 328 (1997).