Enhancement of the colossal magnetoresistance in Eu{sub 1-x}Ca{sub x}B{sub 6}

Journal Article · Sun Aug 15 04:00:00 EDT 2010 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776110080157· OSTI ID:21443441

Anisimov, M A; Bogach, A V; Demishev, S V ^[1]; Dukhnenko, A V ^[2]; Kuznetsov, A V ^[3]; Levchenko, A V ^[2]; Samarin, N A ^[1]; Filippov, V B ^[2]; Churkin, O A ^[3]; Shitsevalova, N Yu ^[2]; Sluchanko, N E ^[1]

---

1. Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)
2. National Academy of Sciences of Ukraine, Frantsevich Institute for Problems of Materials Science (Ukraine)
3. National Research Nuclear University MEPhI (Russian Federation)

The transport and magnetic properties of single crystal samples of substitutional solid solutions Eu{sub 1-x}Ca{sub x}B{sub 6} (0 {<=} x {<=} 0.26) have been studied at temperatures 1.8-300 K in magnetic fields up to 80 kOe. It has been shown that an increase in the calcium concentration results in the suppression of the charge transport accompanied by an increase in the amplitude of the colossal magnetoresistance (CMR) up to the value ({rho}(0) - {rho}(H))/{rho}(H) {approx} 7 x 10{sup 5} detected for x = 0.26 at liquid-helium temperature in a field of 80 kOe. The transition from the hole-like conductivity to the electron-like conductivity has been observed in the Eu{sub 0.74}Ca{sub 0.26}B{sub 6} solid solution in the CMR regime at T < 40 K. The Hall mobility values {mu}H = 200-350 cm{sup 2}/(V s) estimated for charge carriers in the strongly disordered matrix of the Eu{sub 0.74}Ca{sub 0.26}B{sub 6} solid solution are comparable with the charge carrier mobility {mu}H = 400-600 cm{sup 2}/(V s) for the undoped EuB{sub 6} compound. The anomalous behavior of the transport and magnetic parameters of the Eu{sub 1-x}Ca{sub x}B{sub 6} solid solutions is discussed in terms of a metal-insulator transition predicted within the double exchange model for this system with low carrier density.

• OSTI ID: 21443441
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 2 Vol. 111; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
AMPLITUDES
BORIDES
BORON COMPOUNDS
CALCIUM BORIDES
CALCIUM COMPOUNDS
CARRIER DENSITY
CARRIER MOBILITY
CHARGE CARRIERS
CHARGE TRANSPORT
CONCENTRATION RATIO
CRYSTALS
DIMENSIONLESS NUMBERS
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EUROPIUM BORIDES
EUROPIUM COMPOUNDS
HALL EFFECT
HOLES
HOMOGENEOUS MIXTURES
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETORESISTANCE
MIXTURES
MOBILITY
MONOCRYSTALS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SOLID SOLUTIONS
SOLUTIONS
TEMPERATURE DEPENDENCE