For materials that harbour a continuous phase transition, the susceptibility of the material to various fields can be used to understand the nature of the fluctuating order and hence the nature of the ordered state. Here we use anisotropic biaxial strain to probe the nematic susceptibility of URu2Si2, a heavy fermion material for which the nature of the low temperature 'hidden order' state has ...

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...

The structure of single crystals of the organic metals aand /?-(BEDT-TTF)2I3* was determined at 100 K, well below the phase transitions indicated by resistivity and thermopower measurements as well as by differential thermal analysis. In the a-phase no unusual change of the room temperature unit cell but a slight variation in the triiodide network and especially a more pronounced dimerization i...

We study theoretically a triangular cluster of three magnetic impurities, hybridizing locally with conduction electrons of a metallic host. Such a cluster is the simplest to exhibit frustration, an important generic feature of many complex molecular systems in which different interactions compete. Here, low-energy doublet states of the trimer are favored by effective exchange interactions produ...

Magnetic properties of a Heisenberg diamondlike spin chain model for purely organic molecule-based ferrimagnets are investigated by means of the many-body Green's function method within random phase approximation. The molecule-based ferrimagnet is composed of S=1 biradical and S=1/2 monoradical molecules alternating with intermolecular antiferromagnetic (AF) interactions, and the S=1 site is co...

A structural phase transition has been found using electron diffraction technique in PrRu4P12 accompanied by a metal insulator (M I) transition (TMI = 60K). Weak superlattice spots appeared at (H, K, L) (H + K + L = 2n + 1; n is an integer) position at a temperature of T = 12 K and 40 K. Above T = 70 K, the spots completely vanished. The space group of the low temperature phase is probably Pm 3...

We report an investigation on the properties of 0.33 ML of Sn on Ge(111) at temperatures down to 5 K. Low-energy electron diffraction and scanning tunneling microscopy show that the (3x3) phase formed at approximately 200 K, reverts to a new ((square root 3)x(square root 3))R30 degrees phase below 30 K. The vertical distortion characteristic of the (3x3) phase is lost across the phase transitio...

An understanding of water's anomalies is closely linked to an understanding of the phase diagram of water's metastable noncrystalline states. Despite the considerable effort, such an understanding has remained elusive and many puzzles regarding phase transitions in supercooled liquid water and their possible amorphous proxies at low temperatures remain. Here, decompression of very high density ...

We report a first-order phase transition at TM=357 K in single crystal Ca2RuO4, an isomorph to the superconductor Sr2RuO4. The discontinuous decrease in electrical resistivity signals the near d e struction of the Mott insulating phase and is triggered by a s t ructural transition from the low temperature orthorhombic to a high temperature tetragonal phase. The magnetic susceptibility, which is...

Fe-doped MnNiGe alloys were successfully synthesized by solid-state reaction. Giant negative thermal expansion (NTE) behaviors with the coefficients of thermal expansion (CTE) of -285.23 × 10-6 K-1 (192-305 K) and -1167.09 × 10-6 K-1 (246-305 K) have been obtained in Mn0.90Fe0.10NiGe and MnNi0.90Fe0.10Ge, respectively. Furthermore, these materials were combined with Cu in order to control the N...