Phase inhomogeneities and lattice expansion near T-c in the (MgB2)-B-11 superconductor

Authors
Margadonna, S Muranaka, T Prassides, K Maurin, I Brigatti, K Ibberson, RM Arai, M Takata, M Akimitsu, J
Citation
S. Margadonna et al., Phase inhomogeneities and lattice expansion near T-c in the (MgB2)-B-11 superconductor, J PHYS-COND, 13(35), 2001, pp. L795-L802
Citations number
25
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHYSICS-CONDENSED MATTER
ISSN journal
09538984 → ACNP
Volume
13
Issue
35
Year of publication
2001
Pages
L795 - L802
Database
ISI
SICI code
0953-8984(20010903)13:35<L795:PIALEN>2.0.ZU;2-3
Abstract
High-resolution powder neutron diffraction has been used to study the cryst al structure of the (MgB2)-B-11 superconductor (T-c = 39.2 K) prepared at h igh pressure in the temperature range 2 to 293 K. The experimental data pro vide clear evidence of temperature-independent phase inhomogeneity, which w as modelled by coexisting Mg1+deltaB2 phases. Precise structural informatio n for temperatures near T-c also reveals extremely small volume and c-axis discontinuities, consistent with the existence of a specific heat anomaly a t T-c.