The isostructural α-γ phase transition in cerium is analyzed using density-functional theory with different exchange-correlation functionals, in particular the PBE0 hybrid functional and the exact-exchange plus correlation in the random-phase approximation [(EX+cRPA)@PBE0] approach. We show that the Hartree-Fock exchange part of the hybrid functional gives rise to two distinct solutions at zero...

The results of the linear thermal expansion studies on (CH3NH3)5Bi2Br11 single crystals in the temperature range 60–340 K are presented. The thermal anomaly in the vicinity of 77 K is assigned to the phase transition classified as close to first order type. The pyroelectric measurements of (CH3NH3)5Bi2Br11 were carried out in the range of 45–320 K along the aand c-axis. The step-like change in ...

The phases and excitation spectrum of an easy-axis ferromagnetic chain of S = 1/2 magnetic impurities built on the top of a clean metallic surface are studied. As a function of the (Kondo) coupling to the metallic surface and at low temperatures, the spin chain exhibits a quantum phase transition from an Ising ferromagnetic phase with long-range order to a paramagnetic phase where quantum fluct...

We analyze the interplay of dissipative and quantum effects in the proximity of a quantum phase transition. The prototypical system is a resistively shunted two-dimensional Josephson junction array, studied by means of an advanced Fourier path-integral Monte Carlo algorithm. The reentrant superconducting-to-normal phase transition driven by quantum fluctuations, recently discovered in the limit...

A novel order parameter Φ for spin glasses is defined based on topological criteria and with a clear physical interpretation. Φ is first investigated for well known magnetic systems and then applied to the Edwards-Anderson ±J model on a square lattice, comparing its properties with the usual q order parameter. Finite size scaling procedures are performed. Results and analyses based on Φ confirm...

Low temperature scanning tunneling microscopy measurements on the adsorption of single Pb adatoms on Si(111)-(square root 3 x square root 3)-Pb surfaces reveal the vertical displacement patterns induced on the substrate by these Pb adatoms as well as a novel adatom-adatom interaction. The origin of both can be traced back to the (square root 3 x square root 3)<-->(3 x 3) phase transition taking...

The three-dimensional, three-state Potts model is studied as a paradigm for high temperature quantum chromodynamics. In a high statistics numerical simulation using a Swendson-Wang algorithm, we study cubic lattices of dimension as large as 643 and measure correlation functions on long lattices of dimension 202 × 120 and 302 × 120. These correlations are controlled by the spectrum of the transf...

In material selection, especially in low temperature conditions, one of very important factors it is a ductile to brittle transition temperature, i.e. the temperature when material becomes too brittle to use. In this paper transition temperature determined by impact energy in temperature interval from –196 to +100°C of unalloyed austempered ductile iron with different microstructures have been ...

Using Hartree-Fock Su-Sheriffer-Heeger (HF-SSH) model, we have studied the dependence of the energies of the ground (magnetic triplet state) and the first exited (nonmagnetic singlet state) states of the size-2 trigonal zigzag graphene nanoflake (size-2 NF) on the intensity of an external in plane static electric field at zero temperature. We identify a transition from the magnetic triplet stat...