Microwave Surface Impedance and Nonlinear Properties of MgB2 Films

Published

June 1, 2003

Author(s)

James Booth, Sang Y. Lee, Kenneth Leong, J. H. Lee, J. Lim, H. N. Lee, S. H. Moon, B. Oh

Abstract

We have measured the temperature dependence of the microwave surface impedance and the nonlinear response of high-quality MgB₂ films on c-cut sapphire at temperatures below 40 K. MgB₂ films with surface resistance (Rs) as low as 0.09 mOhm} at 8 K and 19.6 GHz were prepared in an ex-situ process by annealing a boron layer in magnesium-rich environment. The nonlinear properties of the MgB₂ films were investigated as a function of temperature by means of higher order harmonic generation measurements in patterned coplanar waveguide devices. The effects of surface ion-milling on the nonlinear properties of MgB₂ films were also studied, and the nonlinear response of MgB₂ films was compared with that of epitaxially grown YBCO films. The consequences of these measurements for passive microwave device applications of MgB₂ films are also discussed.

Citation

IEEE Transactions on Applied Superconductivity

Volume

13

Issue

2

Pub Type

Journals

Keywords

magnesium diboride, nonlinear microwave response, superconductor

Citation

Booth, J. , Lee, S. , Leong, K. , Lee, J. , Lim, J. , Lee, H. , Moon, S. and Oh, B. (2003), Microwave Surface Impedance and Nonlinear Properties of MgB₂ Films, IEEE Transactions on Applied Superconductivity (Accessed April 19, 2024)