Glassy crystals with colossal multi-baroresponsivities

TL;DR

This paper reports the discovery of a glassy-crystal state in a specific compound, exhibiting colossal responses to pressure and temperature changes, with potential applications in sensors and memory devices.

Contribution

The study identifies and characterizes a novel glassy-crystal state in AMP, demonstrating its extreme sensitivity to pressure and temperature, and exploring its potential technological applications.

Findings

VFT law describes relaxation times in the glassy-crystal state

Pressure induces rapid crystallization and significant property changes

Ultrasensitive baroresponsivity observed at room temperature

Abstract

As a nontrivial solid state of matter, the glassy-crystal state embraces physical features of both crystalline and amorphous solids, where a long-range ordered periodic structure formed by the mass centers of constituent molecules accommodates orientational glasses. Here, we discover and validate a glassy-crystal state in 2-amino-2-methyl-1,3-propanediol (AMP, C4H11NO2) by neutron scattering and complementary broadband dielectric spectroscopy (BDS) measurements. The freezing process of the dynamic orientational disorder is manifested at relaxation times well described by the Vogel-Fulcher-Tammann (VFT) law and the strongly frequency-dependent freezing temperature ranging from around 225 K at 0.1 Hz to above room temperature in the GHz region. At room temperature, the supercooled state is extremely sensitive to pressure such that a few MPa pressure can induce crystallization to the ordered crystal state, eventually leading to a temperature increase by 48 K within 20 s, a significant reduction of visible light transmittance from about 95% to a few percentages, and a remarkable decrease of electrical conductivity by three orders of magnitude. These ultrasensitive baroresponsivities might find their applications in low-grade waste heat recycling, pressure sensors and non-volatile memory devices. It is expected that glassy crystals serve as an emerging platform for exploiting exotic states of matter and the associated fantastic applications.