RESUMO
Binary ruthenium dioxide (RuO2) has gradually attracted much attention in condensed matter physics and material sciences due to its various intriguing physical properties, such as strain-induced superconductivity, anomalous Hall effect, collinear anti-ferromagnetism, etc. However, its complex emergent electronic states and the corresponding phase diagram over a wide temperature range remain unexplored, which is critically important to understanding the underlying physics and exploring its final physical properties and functionalities. Here, through optimizing the growth conditions by using versatile pulsed laser deposition, high-quality epitaxial RuO2thin films with clear lattice structure are obtained, upon which the electronic transport is investigated, and emergent electronic states and the relevant physical properties are unveiled. Firstly, at a high-temperature range, it is the Bloch-Grüneisen state, instead of the common Fermi liquid metallic state, that dominates the electrical transport behavior. Moreover, the recently reported anomalous Hall effect is also revealed, which confirms the presence of the Berry phase in the energy band structure. More excitingly, we find that above the superconductivity transition temperature, a new positive magnetic resistance quantum coherent state with an unusual dip as well as an angel-dependent critical magnetic field emerges, which can be attributed to the weak antilocalization effect. Lastly, the complex phase diagram with multiple intriguing emergent electronic states over a wide temperature range is mapped. The results greatly promote the fundamental physics understanding of the binary oxide RuO2and provide guidelines for its practical applications and functionalities.
RESUMO
Liquid-liquid transition of water is an important concept in condensed-matter physics. Recently, it was claimed to have been confirmed in aqueous solutions based on annealing-induced upshift of glass-liquid transition temperature, T(g) . Here we report a universal water-content, X(aqu) , dependence of T(g) for aqueous solutions. Solutions with X(aqu)>X(cr)(aqu)vitrify/devitrify at a constant temperature, ~T(g) , referring to freeze-concentrated phase with X(aqu)left behind ice crystallization. Those solutions with X(aqu)
RESUMO
While the vapour-liquid-solid process has been widely used for growing one-dimensional nanostructures, quantitative understanding of the process is still far from adequate. For example, the origins for the growth of periodic one-dimensional nanostructures are not fully understood. Here we observe that morphologies in a wide range of periodic one-dimensional nanostructures can be described by two quantitative relationships: first, inverse of the periodic spacing along the length direction follows an arithmetic sequence; second, the periodic spacing in the growth direction varies linearly with the diameter of the nanostructure. We further find that these geometric relationships can be explained by considering the surface curvature oscillation of the liquid sphere at the tip of the growing nanostructure. The work reveals the requirements of vapour-liquid-solid growth. It can be applied for quantitative understanding of vapour-liquid-solid growth and to design experiments for controlled growth of nanostructures with custom-designed morphologies.