Related papers: First order valence transition in YbInCu_4 in the …
As it was shown earlier [Dzero, Gor'kov, and Zvezdin, J. Phys.:Condens. Matter 12, L711 (2000)] the properties of the first-order valence phase transition in YbInCu4 in the wide range of magnetic fields and temperatures are perfectly…
For describing the first-order isostructural valence phase transition in mixed valence compounds we develop a new approach based on the lattice Anderson model. We take into account the Coulomb interaction between localized f and conduction…
A diffraction experiment using a high energy x-ray was carried out on YbInCu4. Below the Yb valence transition temperature, the splitting of Bragg peaks was detected in higher-order reflections. No superlattice reflections accompanying the…
The pressure-temperature phase diagram of an intermediate-valence compound YbPd was revealed via simultaneous ac-calorimetry and electrical resistivity measurements. Two successive structural phase transition temperatures, $T_1$ = 125 K and…
We have investigated the magnetic phase diagram of a fully oxygenated detwinned YBa2Cu3O7 single crystal by means of magneto-caloric and magnetization measurements, and found thermodynamic evidence for a temperature dependent first-order…
YbInCu$_4$ undergoes a first order structural phase transition near $T_v$=40 K associated with an abrupt change of Yb valence state. We perform ultrafast pump-probe measurement on YbInCu$_4$ and find that the expected heavy fermion…
Pure as well as Ag- and Au-substituted YbInCu$_4$ single crystals were structurally and chemically characterized and investigated by means of heat capacity, magnetization, resistivity and ultrasonic measurements. We studied the influence of…
The following is a thermodynamic analysis of a III order (and some aspects of a IV order) phase transition. Such a transition can occur in a superconductor if the normal state is a diamagnet. The equation for a phase boundary in an H-T (H…
We present an exhaustive analysis of transport measurements performed in twinned YBa2Cu3O7 single crystals which stablishes that the vortex solid-liquid transition is first order when the magnetic field H is applied at an angle theta away…
Specific heat, resistivity, magnetic susceptibility, linear thermal expansion (LTE), and high-resolution synchrotron X-ray powder diffraction investigations of single crystals Fe1+yTe (0.06 < y < 0.15) reveal a splitting of a single,…
A first order phase transition between a BCS phase and an insulating Mott phase for a gas of spatially separated electrons and holes with tunable Coulomb interaction and variable density is predicted. In the framework of a BCS-like…
The nature of the metal-insulator Mott transition at zero temperature has been discussed for a number of years. Whether it occurs through a quantum critical point or through a first order transition is expected to profoundly influence the…
First order phase transitions, where one phase replaces another by virtue of a simple crossing of free energies, are best known between solids, liquids and vapours, but they also occur in a wide range of other contexts, including even…
Quantum phase transitions in Mott insulators do not fit easily into the Landau-Ginzburg-Wilson paradigm. A recently proposed alternative to it is the so called deconfined quantum criticality scenario, providing a new paradigm for quantum…
Bulk studies have revealed a first-order valence phase transition in Ba$_2$PrRu$_{1-x}$Ir$_x$O$_6$ ($0.10 \le x \le 0.25$), which is absent in the parent compounds with $x = 0$ (Pr$^{3+}$) and $x =1$ (Pr$^{4+}$), which exhibit…
Topological quantum phase transitions are characterised by changes in global topological invariants. These invariants classify many body systems beyond the conventional paradigm of local order parameters describing spontaneous symmetry…
While the Heisenberg model for magnetic Mott insulators on planar lattice structures is comparatively well understood in the case of transition metal ions, the intrinsic spin-orbit entanglement of 4f magnetic ions on such lattices shows…
We highlight interesting thermomagnetic history effects across the transition line between the (quasi) ordered and disordered vortex states in single crystal YBa$_2$Cu$_3$O$_{7-\delta}$, and argue that these features are indicative of the…
The anomalous behavior of YbInCu4 and similar compounds is modeled by the exact solution of the spin one-half Falicov-Kimball model in infinite dimensions. The valence-fluctuating transition is related to a metal-insulator transition caused…
Magnetic properties of the Co valence tautomers are considered in wide range of magnetic field and temperature. Particularly, a model of the first order structural phase transition accompanied by a magnetic moment jump is proposed. The…