Direct submillimeter absorptivity measurements on epitaxial Ba{sub 1-x}K{sub x}BiO{sub 3}films at 2K
- Lawrence Berkeley Lab., CA (United States)
- California Univ., Santa Barbara, CA (United States)
- AT and T Bell Labs., Murray Hill, NJ (United States)
- Illinois Univ., Urbana, IL (United States)
- Hewlett-Packard Lab., Palo Alto, CA (United States)
We have used a bolometric technique to obtain accurate low temperature loss data for epitaxial thin films of Ba{sub 0.6}K{sub 0.4}BiO{sub 3} from 30 to 700 cm{sup {minus}1}. These films were grown on MgO and SrTiO{sub 3} substrates by MBE, off-axis sputtering and laser deposition techniques. All films show a strong absorption onset near the BCS tunneling gap of 3.5k{sub B}T{sub c}. We have analyzed these data using a Kramers-Kronig transformation and have corrected for finite film thickness effects. Results indicate that the absorption onset is consistent with a superconducting energy gap. Comparison is made with predictions based on strong coupling Eliashberg theory using {alpha}{sup 2}F({omega}) spectra obtained from the literature. While we are able to fit the overall measured absorptivity, we are unable to fit the structure observed in our data.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 10158289
- Report Number(s):
- LBL-33971; CONF-930367-5; ON: DE93013904; CNN: Grant: STC-90-09854
- Resource Relation:
- Conference: Conference on spectroscopies in novel superconductors,Santa Fe, NM (United States),17-19 Mar 1993; Other Information: PBD: Apr 1993
- Country of Publication:
- United States
- Language:
- English
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