Negative and zero thermal expansion in α-(Cu<sub>2−x</sub>Zn<sub>x</sub>)V<sub>2</sub>O<sub>7</sub> solid solutions
Naike Shi, Andrea Sanson, Alessandro Venier, Longlong Fan, Cheng‐Jun Sun, Xianran Xing, Jun Chen
Abstract
Negative or zero thermal expansion (NTE or ZTE) of materials is intriguing for controllable thermal expansion. We report a series of orthorhombic α-Cu2-xZnxV2O7 (x = 0, 0.1, 0.2), in which the volumetric coefficients of thermal expansion are successfully tuned from -10.19 × 10-6 K-1 to -1.58 × 10-6 K-1 in the temperature range of 100-475 K by increasing the content of Zn2+. It has been revealed that the transverse vibrations of oxygen bonded with vanadium are dominant in the contraction of the bc plane, leading to the overall volume NTE in α-Cu2V2O7. The introduction of Zn2+ densifies the crystal structure, which is presumed to suppress the space of transverse vibrations and results in the ZTE in α-Cu1.8Zn0.2V2O7. This work presents an effective method to realize ZTE in anisotropic framework systems.