Phys.org September 2, 2024 Gold nuggets occur predominantly in quartz veins, and the current paradigm posits that gold precipitates from dilute (<1 mg kg−1 gold), hot, water ± carbon dioxide-rich fluids owing to changes in temperature, pressure and/or fluid chemistry. However, the widespread occurrence of large gold nuggets is at odds with the dilute nature of these fluids and the chemical inertness of quartz. Using quartz deformation experiments and piezoelectric modelling researchers in Australia investigated if piezoelectric discharge from quartz could explain the ubiquitous gold–quartz association and the formation of gold nuggets. They found that stress on quartz crystals could generate enough voltage to […]
Tag Archives: Electricity
A quasiparticle that can transfer heat under electrical control
Science Daily February 1, 2023 An international team of researchers (USA – Ohio State University, Japan) has experimentally shown that an external electric field affects the velocity of the longitudinal acoustic phonons (vLA), thermal conductivity (κ), and diffusivity (D) in a bulk lead zirconium titanate–based ferroelectric. They found that phonon conduction dominates κ due to changes in the phonon dispersion, not in the phonon scattering. Since the ferron carries heat, that makes the amount of heat carried dependent on the electrical field. They wrote a new theory that relates an external electric field, the strain it induces in a ferroelectric, […]