Crystal structure and superconductivity in the Ni-based ternary compound LaNiSi
- Department of Physics, National Chung Cheng University, Ming-Hsiung, Chia-Yi 621, Taiwan (Taiwan, Province of China)
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (Taiwan, Province of China)
With powder-x-ray-diffraction methods, the ternary compound LaNiSi has been identified to have a LaPtSi-type crystal structure with four formula units in a unit cell of the space group [ital I]4[sub 1][ital md] with dimensions [ital a]=4.181(1) A, [ital c]=14.069(8) A. The agreement of the transition temperature [ital T][sub [ital c]]=1.20[similar to]1.26 K (10[similar to]90 % values) measured by ac-susceptibility and heat-capacity techniques provides clear evidence of bulk superconductivity in LaNiSi. The normal-state specific-heat data can be fit to the expression [ital C][sub [ital n]]=[gamma][ital T]+[beta][ital T][sup 3] by a least-squares analysis, where [gamma]=8.89 mJ/mol K[sup 2] and [beta]=0.487 mJ/mol K[sup 4], resulting in a Debye temperature [Theta][sub [ital D]]=229 K. Below [ital T][sub [ital c]], the specific-heat data have a dominant low-temperature behavior of the form exp[[minus][Delta](0)/[ital k][sub [ital BT]]], where the order parameter 2[Delta](0)=3.5[ital k][sub [ital BT]][sub [ital c]]. In addition, the measured heat-capacity jump [Delta][ital C] at the transition point is found to be equal to 1.46[gamma][ital T][sub [ital c]], implying that LaNiSi is a weakly coupled superconductor.
- OSTI ID:
- 6881464
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:9; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
COHERENT SCATTERING
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LANTHANUM COMPOUNDS
LANTHANUM SILICIDES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
NICKEL COMPOUNDS
PHYSICAL PROPERTIES
POLYCRYSTALS
POWDERS
RARE EARTH COMPOUNDS
SCATTERING
SILICIDES
SILICON COMPOUNDS
SPACE GROUPS
SPECIFIC HEAT
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION