Characterization of YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films grown in different orientations

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1992

OSTI ID:6982626

Wu, S

High T[sub c] superconducting YBCO thin films were deposited in our laboratory by 90[degrees] off axis RF sputtering. Substrates used for growing YBCO thin films were (100) MgO, ZrO[sub 2] and SrTiO[sub 3]. Films were grown in different directions: c-axis, a-axis, and ab-axis. C-axis oriented films were readily grown on MgO and ZrO[sub 2]. High quality a-axis film can be grown on SrTiO[sub 3], but not on MgO or ZrO[sub 2]. To improve the quality of a-axis YBCO films grown on MgO and ZrO[sub 2], a technique of using c-axis thin layer as a buffer was developed. By using this technique, T[sub c] of a-axis films grown on MgO was increased from 0 to 70 K and T[sub c] of a-axis films grown on ZrO[sub 2] was increased from 0 to 60 K. The quality of all YBCO films was characterized by X-ray diffraction, SEM, RHEED, and RBS. Finally, the energy gap of YBCO thin films was measured by low temperature STM. The anisotropy in energy gap was observed. Along c-axis, the peak-to-peak separation was about 20 meV, corresponding to 2[delta]/K[sub B]T[sub c] = 3. In the ab-plane, the peak-to-peak separation was about 70 meV, corresponding to 2[delta]/K[sub B]T[sub c] = 8.

• Research Organization: Kentucky Univ., Lexington, KY (United States)
• OSTI ID: 6982626
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ANISOTROPY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
CUPRATES
FILMS
GRAIN ORIENTATION
HIGH-TC SUPERCONDUCTORS
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES