This compound is the ﬁrst superconductor found among the large family of pyrochlore oxides with the formula A2B2O7 , where A is either a rare earth or a late transition metal, and B is a transition metal.
Route to Room-Temperature Superconductivity from a Practical Point of View
Previous studies indicate that the pyrochlores, like the spinels, are geometrically frustrated.
Route to Room-Temperature Superconductivity from a Practical Point of View
Similar DMA experiments were performed on several EuTiO3 ceramics as well as on ceramics with some pyrochlore or amorphous impurities (all samples prepared by the A method).
Antiferrodistortive phase transition in EuTiO3
Maximal shift down of the critical temperature was 60 K in samples with ∼ 2% of pyrochlore impurities.
Antiferrodistortive phase transition in EuTiO3
From Monte Carlo simulation and a simple energy comparison for the pyrochlore double-exchange model, we show that such phase separation takes place between ferromagnetic and paramagnetic metals.
Electronic phase separation in the pyrochlore double-exchange model
We discuss the relevance of our results to a spin-glassy metallic phase found in Mo pyrochlore oxides under external pressure.
Electronic phase separation in the pyrochlore double-exchange model
Here we show that PS takes place between FM and a paramagnetic state for the model deﬁned on the pyrochlore lattice which has a threedimensional network of corner-sharing tetrahedra [inset of Fig. 1(a)].
Electronic phase separation in the pyrochlore double-exchange model
Our model is the DE model deﬁned on the pyrochlore lattice, shown in the inset of Fig. 1(a).
Electronic phase separation in the pyrochlore double-exchange model
The inset shows the cubic unit cell of the pyrochlore lattice. (b) Spin correlation hSi · Sj i for two states on the verge of the phase separation at µc1 ≃ 1.4, plotted as a function of the distance in unit of the nearest-neighbor bond length.
Electronic phase separation in the pyrochlore double-exchange model
The data are measured along the 1D chains in the pyrochlore lattice. (c) and (d) Density of states for the two states.
Electronic phase separation in the pyrochlore double-exchange model
In contrast to the unfrustrated case, our PS obtained for the frustrated pyrochlore model occurs between FM and PM.
Electronic phase separation in the pyrochlore double-exchange model
In fact, in the pyrochlore Heisenberg AF spin system, it is known that any perturbation such as farther-neighbor exchange interactions may force the system to order .
Electronic phase separation in the pyrochlore double-exchange model
To summarize, we have investigated the electronic phase separation in the double-exchange model deﬁned on the frustrated pyrochlore lattice.
Electronic phase separation in the pyrochlore double-exchange model
We discuss that the phase separation explains the peculiar spin-glassy metallic behavior in Mo pyrochlore oxides under external pressure.
Electronic phase separation in the pyrochlore double-exchange model
We discuss candidate materials, including the pyrochlore iridates5 and heterostructures of topological insulators and ferromagnets7 .
Beyond Band Insulators: Topology of Semi-metals and Interacting Phases
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