Superconductivity and magnetism in the pseudoternary system Gd/sub x/Y/sub 1-x/Rh/sub 4/B/sub 4/

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.26.2450· OSTI ID:6774294

Adrian, H; Mueller, R; Behrle, R

The phase boundaries between the paramagnetic, superconducting, and ferromagnetically ordered states of the tetragonal pseudoternary system Gd/sub x/Y/sub 1-x/Rh/sub 4/B/sub 4/ have been determined by ac susceptibility measurements. Magnetization measurements, performed with cylindrical samples for 0< or =x< or =0.45 at temperatures above 1.5 K, show clearly that macroscopic electromagnetic effects are of minor importance in this system and indicate a transition from type-II/2 to type-II/1 or type-I superconductivity at temperatures close to T/sub c/2. For the critical fields we obtain from the magnetization curves a sawtoothlike H/sub c/1(T), scaling with T/sub c/1(x), whereas H/sub c/2(T) is bell shaped for x> or =0.1, with its maximum decreasing exponentially with x for x< or =0.30. From Arrott plots we find spontaneous magnetizations below T/sub m/ and Curie-Weiss laws for the normal-state susceptibility indicating ferromagnetic Curie temperatures THETA/sub C/>0 for x>0.1. Analyzing the data we show that the strength of the exchange interaction between the conduction electrons and the Gd moments deduced from T/sub c/1(x) is strong enough to mediate the indirect interaction between the Gd moments as found from THETA/sub C/(x). From specific-heat measurements carried out for x = 0.25 and 0.45 we obtain N*(E/sub F/) = 0.57 states/(atomBeV spin), in agreement with the nonmagnetic Y and Lu compounds. The details of the magnetic transitions appear to scale with the Gd concentration.

• Research Organization: Physikalisches Institut der Universitaet Erlangen-Nuernberg, D-8520 Erlangen, Bundesrepublik Deutschland
• OSTI ID: 6774294
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 26:5; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORIDES
BORON COMPOUNDS
CRITICAL FIELD
CURIE-WEISS LAW
DATA
DIAGRAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXCHANGE INTERACTIONS
EXPERIMENTAL DATA
FERROMAGNETISM
GADOLINIUM BORIDES
GADOLINIUM COMPOUNDS
INFORMATION
INTERACTIONS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
MAGNETIZATION
NUMERICAL DATA
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
RHODIUM BORIDES
RHODIUM COMPOUNDS
SCALING LAWS
SPECIFIC HEAT
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TYPE-I SUPERCONDUCTORS
TYPE-II SUPERCONDUCTORS
ULTRALOW TEMPERATURE
YTTRIUM BORIDES
YTTRIUM COMPOUNDS