Crack-free and c-axis in-plane aligned superconducting Y0.7Ca0.3Ba2Cu3O7-δ films for terahertz radiating Josephson plasma devices

Yanwei Ma, Kazuo Watanabe, Satoshi Awaji, Mitsuhiro Motokawa

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


External excitation of the Josephson plasma in YBa2Cu3O7-δ by injecting current is expected to result in the emission of light in the terahertz (THz) region. In order to fabricate such THz light emitting devices, one has to grow underdoped (TC = 60 K), c-axis in-plane aligned YBa2Cu3O7-δ films free from cracks. However, the large thermal expansion coefficient of this compound along the c-axis due to the oxygen incorporation makes it difficult to avoid cracking. Here we report that substitution of Y by Ca made it possible to obtain crack-free, 60 K phase Y0.7Ca0.3Ba2Cu3O7-δ films with a larger oxygen deficiency (δ) than YBa2Cu3O7-δ. This experiment is designed so as to compensate the reduction of hole concentration due to the large oxygen deficiency with the hole doping by Ca substitution.

Original languageEnglish
Pages (from-to)6335-6338
Number of pages4
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number11
Publication statusPublished - 2001 Nov


  • Crack formation
  • In-plane alignment
  • Oxide superconductor
  • Thin films
  • YBaCuO

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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