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Thick MgB2 film with (101) oriented micro-crystals
- Source :
-
Physica C . Dec2004, Vol. 416 Issue 3/4, p90-94. 5p. - Publication Year :
- 2004
-
Abstract
- Abstract: Very thick, ∼40μm, clean, and highly textured MgB2 film was effectively grown on an Al2O3 substrate. The fabrication technique was by the hybrid physical-chemical vapor deposition (HPCVD) using B2H6 gas and Mg ingot as the sources. The X-ray diffraction (XRD) analysis shows a highly (101)-oriented MgB2 crystal structure without any impurity detected. There is no signal from the substrate in the XRD spectrum, indicating that the film thickness has exceeded the X-ray penetration length. Scanning electron microscopy (SEM) reveals that the film is composed of highly packed MgB2 micro-crystals with a uniform size distribution of about 2μm in diameter and 0.2μm in thickness. According to the compositional analysis of energy-dispersive X-ray spectroscopy (EDX), no oxygen, hence no MgO, exists in the textured film, consistent with the XRD result. Also, the transport properties are similar to those of a single crystal, indicating a clean film of good crystallite. The zero field transition temperatures are determined as TC(onset)=39.2K and TC(zero)=38.4K, giving a sharp transition typical of a clean sample. The residual resistivity ratio (RRR) is determined as 6.4 and the magnetoresistance (MR) is about 28% at 40K under the applied field of 9T, which are similar to those of a single crystal. The zero temperature upper critical field, HC2(0), is extrapolated as 19 T from the TC(onset) at applied field up to 9T. [Copyright &y& Elsevier]
- Subjects :
- *THICK films
*VAPOR-plating
*ELECTRON microscopy
*SPECTRUM analysis
Subjects
Details
- Language :
- English
- ISSN :
- 09214534
- Volume :
- 416
- Issue :
- 3/4
- Database :
- Academic Search Index
- Journal :
- Physica C
- Publication Type :
- Academic Journal
- Accession number :
- 15426872
- Full Text :
- https://doi.org/10.1016/j.physc.2004.09.009