Related papers: Heavy-Electron Behavior and Structural Change in C…
We report a first-order phase transition at T_M=357 K in single crystal Ca_2RuO_4, an isomorph to the superconductor Sr_2RuO_4. The discontinuous decrease in electrical resistivity signals the near destruction of the Mott insulating phase…
We have measured susceptibility, specific heat, resistivity, and thermopower of CaCu$_3$Ti$_{4-x}$Ru$_x$O$_{12}$ and CaCu$_{3-y}$Mn$_y$Ru$_4$O$_{12}$, and have found that CaCu$_3$Ru$_4$O$_{12}$ can be regarded as a heavy-fermion oxide in…
We study the electronic states for Ca_{2-x}Sr_{x}RuO_{4} in $0.5\leq x \leq 2$ within the Gutzwiller approximation (GA) on the basis of the three-orbital Hubbard model for the Ru t_{2g} orbitals. The main effects of the Ca substitution are…
CeCoSi with no local inversion symmetric crystal structure ($P4/nmm$) exhibits a phase transition of unknown origin (Hidden Order: HO) at about 12 K ($T_0$) above the antiferromagnetic transition temperature ($T_{\rm N}=9.4$ K). The…
We report an electrical transport study in Ca$_{2-x}$Sr$_{x}$RuO$_4$ single crystals at high magnetic fields ($B$). For $x =0.2$, the Hall constant $R_{xy}$ decreases sharply at an anisotropic metamagnetic (MM) transition reaching its value…
In matter, any spontaneous symmetry breaking induces a phase transition characterized by an order parameter, such as the magnetization vector in ferromagnets, or a macroscopic many-electron wave-function in superconductors. Phase…
We show that the pressure-temperature phase diagram of the Mott insulator Ca$_{2}$RuO$_{4}$ features a metal-insulator transition at 0.5GPa: at 300K from paramagnetic insulator to paramagnetic quasi-two-dimensional metal; at $T \leq$ 12K…
The iso-electronic $d^{4}$ compounds of the $4d$ series show rich phase diagrams due to competing spin, charge and orbital degrees of freedom in presence of strong correlations and structural distortions. One such iso-electronic series,…
The filled skutterudite compound SmOs_{4}Sb_{12} was prepared in single crystal form and characterized. The SmOs_{4}Sb_{12} crystals have the LaFe_{4}P_{12}-type structure with lattice parameter a = 9.3085 Angstroms. Specific heat…
The phase diagram of Ca$_{2-x}$Sr$_x$RuO$_4$ has been studied by neutron diffraction on powder and single-crystalline samples. The experiments reveal antiferromagnetic order and structural distortions characterized by tilts and rotations of…
The robust field-insensitive heavy fermion features in Sm$_3$Ru$_4$Ge$_{13}$ and the magnetic phase transition at $T_N \approx$ 5~K are studied using magnetization $M(T)$, specific heat $C_p(T)$, resistivity $\rho(T)$ and thermal…
Experiments of various types on the metallic transition metal oxide compound LiV_{2}O_{4} with the fcc normal-spinel structure are reviewed. The low-temperature T < 10 K data consistently indicate heavy fermion (HF) behaviors characteristic…
Recent experiments have unveiled important properties of the ground state of the elusive heavy fermion $\mathrm{URu_{2}Si_{2}}$. While tetragonal symmetry-breaking was reported below the hidden-order (HO) transition at $T_{HO}\approx17.5$…
At a temperature of roughly 1\,K, \ce{Sr2RuO4} undergoes a transition from a normal Fermi liquid to a superconducting phase. Even while the former is relatively simple and well understood, the superconducting state is not even after 25…
We report a study of magnetic, thermal, and transport properties of La(3+) substituted Sr2RuO4, performed in order to investigate the effects of additional electron doping in this correlated metal. A gradual enhancement of the electronic…
Here, we study the electrical transport and specific heat in 4$d$ based ferromagnetic material SrRuO$_3$ and its Ti substituted SrRu$_{1-x}$Ti$_x$O$_3$ series ($x$ $\le$ 0.7). The SrRuO$_3$ is a metal and shows itinerant ferromagnetism with…
Optical reflectivity measurements were performed on a single crystal of the d-electron heavy-fermion (HF) metal LiV2O4. The results evidence the highly incoherent character of the charge dynamics for all temperatures above T^* \approx 20 K.…
The quasi-skutterudite superconductor La$_3$Co$_4$Sn$_{13}$ undergoes a phase transition at $T^*=152$ K. By measuring the temperature dependence of heat capacity, electrical resistivity, and the superlattice reflection intensity using…
Temperature dependent electrical resistivity, crystal structure and heat capacity measurements reveal a resistivity drop and metal to semiconductor transition corresponding to first order structural phase transition near 400 K in Ca3Co4O9.…
We studied chemical interaction of Sn with H$_2$ by X-ray diffraction methods at pressures of 180-210 GPa. A previously unknown tetrahydride SnH$_4$ with a cubic structure (${fcc}$) exhibiting superconducting properties below ${T}$$_C$ = 72…