Journal of the Physical Society of Japan · 2009 · 47 citations · 10 references
Charge ExcitationsEngineeringLow-dimensional MagnetismSpin-charge ConversionBismuth-based SuperconductorsSpin SystemsMagnetic ResonanceOne-dimensional MagnetismChemistrySpin DynamicMagnetic MaterialsSpin PhenomenonMagnetismQuantum MaterialsSpin DynamicsFe 3DSpin PhysicsAntiferromagnetic InsulatorPhysicsSpecific HeatMysterious Paramagnetic StatesCondensed Matter TheoryQuantum MagnetismSpintronicsNatural SciencesApplied PhysicsCondensed Matter PhysicsFecl 4
In this study, we have investigated a quasi-two-dimensional organic conductor, λ-BETS 2 FeCl 4 , that exhibits a phase transition from a paramagnetic metal to an antiferromagnetic (AF) insulator at a critical temperature ( T MI ∼8.3 K). To investigate the mechanism of a notable phase transition, we studied the thermal properties of the conductor for temperatures down to 0.2 K at zero magnetic field. We observed that the specific heat of the conductor showed a sharp peak at T MI and a Schottky-type hump. The temperature dependence of the excess specific heat clarifies that π and 3d spins do not cooperatively form an AF order at T MI . We concluded that a 3d spin system keeps a paramagnetic state even at the lowest studied temperature.
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