Transparent conducting oxides have become ubiquitous in modern optoelectronics. However, the number of oxides that are transparent to visible light and have the metallic-like conductivity necessary for applications is limited to a handful of systems that have been known for the past 40 years. In this work, we use hybrid density functional theory and defect chemistry analysis to demonstrate that tri-rutile zinc antimonate, ZnSb₂O₆, is an ideal transparent conducting oxide and to identify gallium as the optimal dopant to yield high conductivity and transparency. To validate our computational predictions, we have synthesized both powder samples and single crystals of Ga-doped ZnSb₂O₆ which conclusively show behavior consistent with a degenerate transparent conducting oxide. This study demonstrates the possibility of a family of Sb(V)-containing oxides for transparent conducting oxide and power electronics applications.

The high brilliance of modern synchrotron radiation sources facilitates experiments with high-energy x-rays across a range of disciplines, including the study of the electronic and magnetic correlations using elastic and inelastic scattering techniques. Here we report on Nuclear Resonance Scattering at the 73 keV nuclear level in ¹⁹³Ir. The transitions between the hyperfine split levels show an untypically high E2/M1 multi-polarity mixing ratio combined with an increased sensitivity to certain changes in the hyperfine field direction compared to non-mixing transitions. The method opens a new way for probing local magnetic and electronic properties of correlated materials containing iridium and provides novel insights into anisotropic magnetism in iridates. In particular, unexpected out-of-plane components of magnetic hyperfine fields and non-zero electric field gradients in Sr₂IrO₄ have been detected and attributed to the strong spin-orbit interaction in this iridate. Due to the high, 62% natural abundance of the ¹⁹³Ir isotope, no isotopic enrichment of the samples is required, qualifying the method for a broad range of applications.

When the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr₃Ru₂O₇ can be tuned through quantum criticality with magnetic field at low temperature. Near its critical field B_c it displays the hallmark T-linear resistivity and a $$T\,{{{{{{\mathrm{log}}}}}}}\,(1/T)$$T log ( 1 / T ) electronic heat capacity behaviour of strange metals. However, these behaviours have not been related to any critical fluctuations. Here we use inelastic neutron scattering to reveal the presence of collective spin fluctuations whose relaxation time and strength show a nearly singular variation with magnetic field as B_c is approached. The large increase in the electronic heat capacity and entropy near B_c can be understood quantitatively in terms of the scattering of conduction electrons by these spin-fluctuations. On entering the spin-density-wave ordered phase present near B_c, the fluctuations become stronger suggesting that the order is stabilised through an “order-by-disorder” mechanism.

B-site ordered 4d¹ and 5d¹ double perovskites have a number of potential exotic ground states including multipolar order, quantum spin liquids and valence bond glass states. These arise from the complex interactions of spin-orbital entangled J_eff = 3/2 pseudospins on the geometrically frustrated fcc lattice. The 4d¹ Mo⁵⁺ perovskite Ba₂YMoO₆ has been suggested to have a valence bond glass ground state. Here we report on the low temperature properties of powder samples of isostructural Ba₂LuMoO₆: the only other known cubic 4d¹ perovskite with one magnetic cation. Our muon spectroscopy experiments show that magnetism in this material remains dynamic down to 60 mK without any spin freezing or magnetic order. A singlet-triplet excitation with a gap of Δ = 28 meV is observed in inelastic neutron scattering. These results are interpreted as a disordered valence bond glass ground state similar to Ba₂YMoO₆. Our results highlight the differences of the 4d¹ double perovskites in comparison to cubic 5d¹ analogues, which have both magnetic and multipolar order.

We report critical current measurements of the ${\mathrm{Sr}}_2{\mathrm{RuO}}_4\text{−}{\mathrm{Sr}}_3{\mathrm{Ru}}_2{\mathrm{O}}_7$ eutectic system, a solid mixture of the spin-triplet superconductor ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ and the nearly ferromagnetic metal ${\mathrm{Sr}}_3{\mathrm{Ru}}_2{\mathrm{O}}_7$. Our results reveal that this eutectic forms an unusual superconducting state with features distinct from those of the pure ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ phase. We observe a crossover from Ambegaokar-Baratoff to Ginzburg-Landau type behavior in the temperature dependence of the critical current, similar to the behavior of Josephson weak-link networks in granular high-$T_c$ cuprates. Our results suggest that large regions of ${\mathrm{Sr}}_3{\mathrm{Ru}}_2{\mathrm{O}}_7$ in this solid mixture may become superconducting by an unusual proximity effect.

The layered-ruthenate family of materials possess an intricate interplay of structural, electronic and magnetic degrees of freedom that yields a plethora of delicately balanced ground states. This is exemplified by Ca₃Ru₂O₇, which hosts a coupled transition in which the lattice parameters jump, the Fermi surface partially gaps and the spins undergo a 90^∘ in-plane reorientation. Here, we show how the transition is driven by a lattice strain that tunes the electronic bandwidth. We apply uniaxial stress to single crystals of Ca₃Ru₂O₇, using neutron and resonant x-ray scattering to simultaneously probe the structural and magnetic responses. These measurements demonstrate that the transition can be driven by externally induced strain, stimulating the development of a theoretical model in which an internal strain is generated self-consistently to lower the electronic energy. We understand the strain to act by modifying tilts and rotations of the RuO₆ octahedra, which directly influences the nearest-neighbour hopping. Our results offer a blueprint for uncovering the driving force behind coupled phase transitions, as well as a route to controlling them.