相关论文: Insulating and Conducting Phases of RbC60
Optical measurements on doped C$_{60}$ films provide evidence for a transition from a high temperature conducting phase to a low temperature insulating phase in quenched Rb$_1$C$_{60}$ and K$_1$C$_{60}$ compounds, while Cs$_1$C$_{60}$ did…
The infrared- and Raman-active vibrational modes of C60 were measured in the various structural states of Rb1C60. According to earlier studies, Rb1C60 has an $fcc$ structure at temperatures above ~100C, a linear chain polymer orthorhombic…
Infrared transmission, electron spin resonance, and X-ray diffraction measurements show unambiguously that RbC$_{60}$ and KC$_{60}$ are stable in air, in contrast to Rb$_{6}$C$_{60}$ which decomposes rapidly upon exposure. The specimens…
We present measurements of the low temperature specific heat of single crystals of kappa-(ET)_2Cu[N(CN)_2]Br as a function of the cooling rate through the glasslike structure transition at $\sim$ 80K. We find that rapid cooling produces a…
By direct quenching or post-annealing followed by quenching, we have successfully obtained a series of KxFe2-ySe2 samples with different properties. It is found that the samples directly quenched in the cooling process of growth show…
We develop an effective medium model of thermal conductivity that accounts for both percolation and interface scattering. This model accurately explains the measured increase and decrease of thermal conductivity with loading in composites…
A series of direct numerical simulations of Rayleigh-B\'enard convection, the flow in a fluid layer heated from below and cooled from above, were conducted to investigate the effect of mixed insulating and conducting boundary conditions on…
We propose that the observed low density ``insulating'' phase of a 2D semiconductor system, with the carrier density being just below ($n < n_c$) the so-called critical density where the derivative of resistivity changes sign at low…
Thermal quenching has been used to find metastable materials such as hard steels and metallic glasses. More recently, quenching-based phase control has been applied to correlated electron systems that exhibit metal--insulator, magnetic or…
We report a super-insulating behavior, in a device having granular Pb film on back-gated few-layer $\mathrm{MoS_2}$, below an onset temperature same as the critical temperature $T_{\rm C}\approx7$ K of bulk Pb. Below $T_{\rm C}$, the…
We consider an optical probe that interacts with an ensemble of rare earth ions doping a materialin the shape of a cantilever. By optical spectral hole burning, the inhomogeneously broadenedtransition in the ions is prepared to transmit the…
The electrical transport properties of ultrathin YBCO films have been modified using an electric double layer transistor configuration employing an ionic liquid. The films were grown on SrTiO3 substrates using high pressure oxygen…
We follow the structural transformation in solid C$_{70}$ from the high temperature hcp to a low temperature monoclinic phase using x-ray diffraction studies at controlled cooling-rates from 0.0033 to 0.42 K/min. Rapid cooling of the sample…
To establish the doping-dependent phase diagram in alkali-metal doped C$_{60}$, we synthesize Rb-doped C$_{60}$ samples with different stoichiometries by using the improved wet-chemistry technique. The doping levels determined from the…
The electrical conductance of molecular beam epitaxial Bi on BaF2(111) was measured as a function of both film thickness (4-540 nm) and temperature (5-300 K). Unlike bulk Bi as a prototype semimetal, the Bi thin films up to 90 nm are found…
Superconducting single crystals of Rb-intercalated FeSe compounds Rb$_x$Fe$_{2-y}$Se$_2$ were prepared by using a starting material of Rb$_2$Se as a Rb source. The superconducting properties and the surface microstructures were…
Exploring a backgated low density two-dimensional hole sample in the large $r_s$ regime we found a surprisingly rich phase diagram. At the highest densities, beside the $\nu=1/3$, 2/3, and 2/5 fractional quantum Hall states, we observe both…
First-order phase transition in a highly correlated electron system can manifest as a dynamic phenomenon. The presence of multiple domains of the coexisting phases average out the dynamical effects making it nearly impossible to predict the…
It is well-known that the electric field can induce phase transitions between superconducting, metallic and insulating states in thin-film materials due to its control of the charge carrier density. Since a similar effect on the charge…
Heat transfer is a critical aspect of modern electronics, and a deeper understanding of the underlying physics is essential for building faster, smaller, and more powerful devices with an improved performance and efficiency. In such…