Pressure induced superconductivity in Eu(Ho)Mo/sub 6/S/sub 8/

Journal Article · Tue Mar 20 04:00:00 EST 1984 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.333550· OSTI ID:5154645

Capone, II, D W; Lai Fook, M S; Guertin, R P; Foner, S; Hinks, D G

The Chevrel phases EuMo/sub 6/S/sub 8/ and Eu-rich Eu/sub 1-x/Ho/sub x/Mo/sub 6/S/sub 8/ (x = 0.1 and x = 0.2) are not superconducting at ambient pressure, but they become superconducting above 12 kbar, 7 and 5 kbar, respectively. The T/sub c/ maxima of Ho-doped pseudoternaries are below that of the undoped system (12 K), due to the smaller ionic radius of Ho/sup 3 +/ and to the pairbreaking of the large (10 ..mu../sub B/) Ho ion moment. The superconducting-normal phase boundaries up to 20 kbar for several Eu(Ho)Mo/sub 6/S/sub 8/ samples are compared to those of EuMo/sub 6/S/sub 8/ and a La-doped sample. A Eu/sub 0.6/Ho/sub 0.4/Mo/sub 6/S/sub 8/ sample showed superconductivity at about 3 K and showed a weak maximum in T/sub c/ vs P, indicating a critical concentration of Eu (>0.7) is needed to bring about pressure induced superconductivity in EuMo/sub 6/S/sub 8/ based systems. The high field moment of Ho-doped EuMo/sub 6/S/sub 8/ at 9T is above that of fully saturated Eu/sup 2 +/ ions, but below that of the saturated (Eu/sup 2 +/+Ho/sup 3 +/) ions together, because of crystalline electric field effects on the Ho ions. The results of this work are compared with pure EuMo/sub 6/S/sub 8/ and with EuMo/sub 6/S/sub 8/ samples having controlled oxygen content, and the data are contrasted with data for Eu(La)Mo/sub 6/S/sub 8/, La being a trivalent but nonmagnetic impurity.

• Research Organization: Tufts University, Medford, Massachusetts 02155
• OSTI ID: 5154645
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 55:6; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EUROPIUM ADDITIONS
EUROPIUM ALLOYS
MAGNETIZATION
MOLYBDENUM COMPOUNDS
MOLYBDENUM SULFIDES
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
RARE EARTH ADDITIONS
RARE EARTH ALLOYS
SULFIDES
SULFUR COMPOUNDS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VERY HIGH PRESSURE