Effect of manganese doping on the superconducting transition temperature and the upper critical field of tin-molybdenum-sulfide

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5671864

Miller, W M

The superconducting transition temperature, T/sub c/, and the upper critical field, H/sub c2/(T), of manganese-doped SnMo/sub 6/S/sub 8/(Mn/sub x/Sn/sub 1-x/Mo/sub 6/S/sub 8/) were measured. These samples had reproducible superconducting properties. They were characterized by x-ray powder diffractometry, optical microscopy, electron microscopy, and electron microprobe work. The transition temperature decreased slowly with increasing manganese content until x = 0.06. It then increased until x = 0.10, after which it fell slowly again. Manganese would normally have strong pair-breaking effects on the quasiparticles, but these results provide an exception. X-ray Absorbtion Near-Edge Structure (XANES) measurements showed that the manganese exists as Mn/sup +6/ in the compound. Six of its seven valence electrons are transferred to the Mo/sub 6/S/sub 8/ clusters of the compound. The peak in the T/sub c/ curve is explained by considering the extra electrons transferred to the molybdenum as the manganese doping is increased. H/sub c2/(T) curves upward from 0 to 15 kOe and is linear from 15 to 30 kOe. The curvature of the low-field section increases as the manganese doping is raised from x = 0.0 to x = 0.06. Above x = 0.06 the curvature does not change. The slope of the linear section does not vary with manganese content.

• Research Organization: Illinois Univ., Urbana (USA)
• OSTI ID: 5671864
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
CHALCOGENIDES
CRITICAL FIELD
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MAGNETIC FIELDS
MANGANESE ADDITIONS
MANGANESE ALLOYS
MATERIALS
MOLYBDENUM COMPOUNDS
MOLYBDENUM SULFIDES
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TIN COMPOUNDS
TIN SULFIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE