Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Infrared refractive index of thin YBa[sub 2]Cu[sub 3]O[sub 7] superconducting films

Journal Article · · Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States)
DOI:https://doi.org/10.1115/1.2911329· OSTI ID:6957973
; ; ;  [1]; ;  [2]
  1. Massachusetts Inst. of Technology, Cambridge (United States)
  2. AT and T Bell Lab., Murray Hill, NJ (United States)

This work investigates whether thin-film optics with a constant refractive index can be applied to high-[Tc] superconducting thin films. The reflectance and transmittance of YBa[sub 2]Cu[sub 3]O[sub 7] films on LaAlO[sub 3] substrates are measured using a Fourier-transform infrared spectrometer at wavelengths from 1 to 100 [mu]m at room temperature. The reflectance of these superconducting films at 10K in the wavelength region from 2.5 to 25 [mu]m is measured using a cryogenic reflectance accessory. The film thickness varies from 10 to 200 nm. By modeling the frequency-dependent complex conductivity in the normal and superconducting states and applying electromagnetic-wave theory, the complex refractive index of YBa[sub 2]Cu[sub 3]O[sub 7] films is obtained with a fitting technique. It is found that a thickness-independent refractive index can be applied even to a 25nm film, and average values of the spectral refractive index for film thicknesses between 25 and 200 nm are recommended for engineering applications.

OSTI ID:
6957973
Journal Information:
Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 114:3; ISSN JHTRAO; ISSN 0022-1481
Country of Publication:
United States
Language:
English