Chemical Diversity for Tailoring Negative Thermal Expansion

Abstract

Negative thermal expansion (NTE), referring to the lattice contraction upon heating, has been an attractive topic of solid-state chemistry and functional materials. The response of a lattice to the temperature field is deeply rooted in its structural features and is inseparable from the physical properties. For the past 30 years, great efforts have been made to search for NTE compounds and control NTE performance. The demands of different applications give rise to the prominent development of new NTE systems covering multifarious chemical substances and many preparation routes. Even so, the intelligent design of NTE structures and efficient tailoring for lattice thermal expansion are still challenging. However, the diverse chemical routes to synthesize target compounds with featured structures provide a large number of strategies to achieve the desirable NTE behaviors with related properties. The chemical diversity is reflected in the wide regulating scale, flexible ways of introduction, and abundant structure–function insights. It inspires the rapid growth of new functional NTE compounds and understanding of the physical origins. In this review, we provide a systematic overview of the recent progress of chemical diversity in the tailoring of NTE. The efficient control of lattice and deep structural deciphering are carefully discussed. This comprehensive summary and perspective for chemical diversity are helpful to promote the creation of functional zero-thermal-expansion (ZTE) compounds and the practical utilization of NTE.

Hydrogen Bond-Driven Order–Disorder Phase Transition in the Near-Room-Temperature Nonlinear Optical Switch [Ag(NH3)2]2SO4

“…Such a hydrogen bonding weakening-driven negative thermal expansion (along the c axis, −3%) is unique and rare. 40 …”

Molecular tiltation and supramolecular interactions induced uniaxial NTE and biaxial PTE in bis-imidazole-based co-crystals

“…1 In contrast, some materials shrink upon heating, known as Negative Thermal Expansion (NTE). 2,3 PTE of materials is mostly accounted by the asymmetric shape of the Leonard-Jones potential energy curve of a diatomic bond where the distance between the atoms increases with the increase in temperature, resulting in expansion. However, different mechanisms have been reported for NTE depending on the nature of materials, crystal structure, types of interaction, etc.…”

“…However, different mechanisms have been reported for NTE depending on the nature of materials, crystal structure, types of interaction, etc. 2,3 Some of these mechanisms are the presence of low-frequency phonon modes, 3 a the presence of rigid unit modes (RUMs), 3 b transverse vibrations of atoms, 3 c – g geometric flexibility, 3 h – j host-guest interactions, 3 k – n spin crossover, 3 o molecular packing, 3 p change of molecular conformation, 3 q and phase transitions. 3 s Designing molecules with controlled thermal expansion is highly challenging because the mechanism of NTE changes from molecule to molecule.…”

“…3 k , l Recently, research interest in the field of NTE materials has gained attention due to their wide range application in aerospace technologies, electronics, high precision optical mirrors, fibreoptics, organic light-emitting diode (OLEDs), organic field-effect transistors (OFETs), sensors, and thermomechanical actuators. 2,5…”

Unexpected low thermal expansion coefficients of pentadiamond

“…precision instruments, thermal expansion is a critical parameter for materials, and the low LTEC is of benefit for thermal shock resistance, especially for brittle materials, such as diamond. In the past few decades, there has been much progress in the negative thermal expansion, 10 and some new theories are proposed to explain the NTE, such as zentropy theory. 11 However, in carbon allotropes, though the low or negative thermal expansion (NTE) is common in 0D to 2D density of states (DOS) and electronic DOS, and the detailed formulas are listed in ref.…”