Domain Wall Damping and Elastic Softening in SrTiO 3 : Evidence for Polar Twin Walls

摘要: A marked change in anelastic properties, namely, elastic softening accompanied by increased damping, has been observed a single crystal of ${\mathrm{SrTiO}}_{3}$ below $\ensuremath{\sim}50\text{ }\text{ }\mathrm{K}$ resonant ultrasound spectroscopy. This correlates with other subtle changes structure and properties which have explained the past terms novel quantum state formation polar clusters an incipient ferroelectric structure. Comparison new data, obtained at frequencies near 1 MHz, mechanical spectroscopy data collected few Hz or kHz, reveals distinct dispersion frequency is interpreted acoustic loss mechanism depends primarily on mobility under stress ferroelastic twin walls. In most materials, it found that walls become immobile some low-temperature interval due to pinning effects defects. It proposed instead for associated local atomic displacements within such their becomes enhanced. We propose structural not correlated bulk material but relates increasing polarity interpretation implies domain low temperatures.