The properties of an organic molecular ferromagnet [C(60)TDAE(0.86); TDAE is tetrakis(dimethylamino)ethylene] with a Curie temperature ;T(c) = 16.1 kelvin are described. ferromagnetic state shows no remanence, and the dependence magnetization below does not follow behavior expected conventional ferromagnet. These results interpreted as reflection three-dimensional system leading to soft

CeRhIn5 is a new heavy-electron material that crystallizes in quasi-2D structure can be viewed as alternating layers of CeIn3 and RhIn2 stacked sequentially along the tetragonal c axis. Application hydrostatic pressure induces first-order-like transition from an unconventional antiferromagnetic state to superconducting with T(c) = 2.1 K.

We report the observation of heavy-fermion superconducitivity in CeCoIn5 at Tc =2.3 K. When compared to pressure-induced its cubic relative CeIn3 (Tc ~200 mK), is remarkably high. suggest that this difference may arise from magnetically mediated superconductivity layered crystal structure .

The microscopic magnetic properties of the ${\mathrm{CuO}}_{2}$ planes in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.63}$ (${\mathit{T}}_{\mathit{c}}$=62 K) have been investigated Cu and O NMR experiments. Unlike fully oxygenated Y-Ba-Cu-${\mathrm{O}}_{7}$ (${\mathit{T}}_{\mathit{c}}$\ensuremath{\simeq}90 K), various components Knight-shift tensors show strong but identical temperature dependences normal state. This supports picture that there is only one spin component planes....

Transport, thermal, and magnetic data for the heavy electron system ${\mathrm{URu}}_{2}$${\mathrm{Si}}_{2}$ indicate that a charge- or spin-density-wave transition opens an energy gap of \ensuremath{\sim}11 meV over portion Fermi surface below ${\mathrm{T}}_{0}$\ensuremath{\approxeq}17.5 K demonstrate bulk superconductivity occurs ${\mathrm{T}}_{\mathrm{c}}$\ensuremath{\approxeq}1.5 K. The pressure dependences ${\mathrm{T}}_{0}$ ${\mathrm{T}}_{\mathrm{c}}$ support this interpretation....

CeIrIn5 is a member of new family heavy-fermion compounds and has Sommerfeld specific heat coefficient 720 mJ/mol-K2. It exhibits bulk, thermodynamic transition to superconducting state at Tc=0.40 K, below which the decreases as T2 small residual T-linear value. Surprisingly, electrical resistivity drops instrumental resolution much higher temperature T0=1.2 K. These behaviors are highly reproducible field-dependent studies indicate that T0 Tc arise from same underlying electronic structure....

The local atomic structure of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ ( $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.12,$ 0.21, and 0.25) has been studied using pair-distribution-function analysis neutron powder-diffraction data. A change is seen in the which can be correlated with metal-insulator transition $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.21$ 0.25 samples. This structural modeled as an isotropic collapse oxygen towards Mn...

Low temperature specific heat and thermal conductivity measurements on the ambient pressure heavy fermion superconductors CeIrIn5 CeCoIn5 reveal power law dependences of these quantities below T$_c$. The low in both includes T$^2$ terms, consistent with presence nodes superconducting energy gap. data present a T-linear term universal limit (CeIrIn5), T$^3$ variation clean (CeCoIn5), also accord prediction for an unconventional superconductor lines nodes.

Heavy-electron metals exhibit highly correlated electronic behavior at liquid helium temperatures, with conduction-electron masses some hundred times the free-electron mass. Whether "normal," antiferromagnetic, or superconducting, their differs drastically from ordinary metallic counterparts. The physical origin of large mass and unusual superconducting magnetic properties is strong coupling between conduction electrons local ƒ-electron moment fluctuations characteristic these materials.

A series of ionic liquids containing different paramagnetic anions have been prepared and all show behavior with potential applications for magnetic electrochromic switching as well novel transport; also, the tetraalkylphosphonium-based reveal anomalous behavior.

Strong magnetic fluctuations can provide a coupling mechanism for electrons that leads to unconventional superconductivity. Magnetic order and superconductivity have been found coexist in number of magnetically mediated superconductors, but these parameters generally compete. We report close the upper critical field, CeCoIn 5 adopts multicomponent ground state simultaneously carries cooperating superconducting orders. Suppressing first-order transition at field simultaneous collapse order,...

UTe2 is a newly-discovered unconventional superconductor wherein multicomponent topological superconductivity anticipated based on the presence of two superconducting transitions and time-reversal symmetry breaking in state. The observation transitions, however, remains controversial. Here we demonstrate that single crystals displaying an optimal transition temperature at 2 K exhibit remarkably high quality supported by their small residual heat capacity state large resistance ratio. Our...

We present results of temperature and magnetic field dependent resistivity ρ(H,T) bulk magnetization M(H,T) measurements on post-annealed La0.7Ca0.3MnO3 thin films that were grown via pulsed-laser deposition. Both the anomalously large negative magnetoresistance peak near ferromagnetic ordering (Tc=250 K), with Δρ/ρ0=−85% at 50 kOe. A clear correlation is found between ρ M described by phenomenological expression ρ(H,T)∝exp[−M(H,T)/M0]. This reflects important interplay transport magnetism...

Electrical resistivity measurements on a single crystal of the heavy-fermion superconductor CeCoIn5 at pressures to 4.2 GPa reveal strong crossover in transport properties near P(*) approximately 1.6 GPa, where T(c) is maximum. The temperature-pressure phase diagram constructed from these data provides natural connection cuprate physics, including possible existence pseudogap.

We present resistivity \ensuremath{\rho}(T), susceptibility \ensuremath{\chi}(T), and specific heat C(T) data for ${\mathrm{Ce}}_{3}$${\mathrm{Bi}}_{4}$${\mathrm{Pt}}_{3}$. The exhibits a broad maximum centered near 80 K, typical of somewhat-heavy-electron compound; were the material metallic, linear coefficient \ensuremath{\gamma}=75 mJ/mol Ce ${\mathrm{K}}^{2}$ would be expected. However, compound is InotR as indicated by its which rises to large values at low temperatures activated...

We report the discovery of a superconducting transition in heavy-fermion compound ${\mathrm{CeRh}}_{2}$${\mathrm{Si}}_{2}$ under hydrostatic pressure. Superconductivity appears at pressures above about 9 kbar, near critical pressure required to suppress antiferromagnetic order [${\mathit{T}}_{\mathit{N}}$(P=0)=36 K]. Onset superconductivity occurs temperature \ensuremath{\approxeq}350 mK. Resistivity measurements as function field constant allow us build an ${\mathit{H}}^{\mathrm{*}}$-T...

The superconducting phase transition in heavy fermion CeCoIn5 (T(c)=2.3 K zero field) becomes first order when the magnetic field H parallel [001] is greater than 4.7 T, and temperature below T0 approximately 0.31T(c). change from second at lower fields reflected strong sharpening of both specific heat thermal expansion anomalies associated with transition, a magnetocaloric effect, steplike sample volume. This effect due to Pauli limiting type-II superconductor, was predicted theoretically mid-1960s.

The influence of hydrostatic pressure on the electrical resistivity \ensuremath{\rho} and ferromagnetic transition temperature ${\mathit{T}}_{\mathit{c}}$ ${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ca}}_{\mathit{x}}$${\mathrm{MnO}}_{3}$ is presented for x=0.21, 0.33, 0.40. Pressure strongly decreases drives up at rates as large +37 K/GPa x=0.21 specimen; this significantly larger than ${\mathit{dT}}_{\mathit{c}}$/dP values observed in conventional ferromagnets about eight...