Multifunctional High-Temperature Phase-Transition Energy Storage Material with Coexistence of Electrical–Thermal Double Switches:[(C₆H₁₅BrNO)₂MBr₄] (M = Cd and Zn)

Abstract

Two novel semiconductor organic–inorganic hybrid perovskites [(C6H15BrNO)2MBr4] (M = Cd for 1 and Zn for 2) were successfully synthesized, which undergo a high-temperature reversible transition at T c (T c = 379 K for 1, 407 K for 2). Differential scanning calorimetry (DSC) curve test shows that there is a pair of reversible thermal abnormal peaks at 379/348 K for compound 1 during the heating/cooling process, and the thermal hysteresis loop is ∼31 K. For compound 2, there is a pair of reversible thermal anomaly peaks at 407/375 K, and the thermal hysteresis loop is ∼33 K, indicating that the phase transition to a first-order phase transition. The dielectric test further confirmed the phase transition. X-ray single-crystal diffraction analysis showed that the space groups of compounds 1 and 2 at 300 K belong to C2/c and P 21/ c , and the temperature-variable powder X-ray diffraction (PXRD) test proved that compounds 1 and 2 had reversible structural phase transition. In addition, both UV–vis diffuse reflectance spectroscopy and density functional theory (DFT) calculations have confirmed that both compounds 1 and 2 are direct band gaps, with values of 4.116 and 4.205 eV, respectively. The above results show that 1 and 2 have fast switchable dielectric properties and potential applications in semiconductor materials.

A 1D chiral infinite chain organic metal halide hybrid with excellent SHG switching and moderate spontaneous polarization

“…The results reveal that 1 has three obvious diffraction peaks that appear near 22.91, 27.01 and 46.01 below T c , but these peaks (22.91, 27.01, 46.01) disappear when the temperature decreases above T c . It returns to the initial state after cooling down above T c , as expected, and these phenomena indeed indicate that 1 undergoes a reversible phase transition 28.…”

“…It returns to the initial state after cooling down above T c , as expected, and these phenomena indeed indicate that 1 undergoes a reversible phase transition. 28 From the DSC and variable-temperature PXRD analysis, it is proposed that 1 might demonstrate switchable quadratic NLO effects. The variable temperature SHG signal is a powerful method for detecting symmetry breaking in the crystal structure.…”

“…Organic metal halide hybrid (OMHH) materials have a myriad of commercial and industrial applications, and display rich and excellent physical properties, such as superconductivity, magnetoresistance, ferroelectricity, and ionic conductivity. [1][2][3][4] The lead halide hybrids constructed with organic ammonium cations and inorganic Pb halide frameworks are one of the most studied families of OMHH. DongPeng Yan et al reported a 1D organic-inorganic hybrid perovskite micro-belt (AD)Pb 2 Cl 5 , which presents upconversion fluorescence, polarized photoemission and optical waveguide performances with a low loss coefficient (0.004 dB mm À1 ) during propagation.…”

“…In this context, a new 1D infinite one chain lead-free pentahalide ferroelectric OMHH (C 4 H 10 NO) 2 SbCl 5 (1). The structure can be described as an infinite inorganic chain formed by two adjacent [SbCl 6 ] 3À octahedra, and the cations are fixed between chain-chain by hydrogen bonds, and the cations are fixed between chain-chain by hydrogen bonds.…”

Unusual high-temperature host–guest inclusion compound-based ferroelectrics with nonlinear optical switching and large spontaneous polarization behaviours

“…2,3 Therefore, it has a wide range of applications in storage components, drivers, sensors, etc. 4 Although inorganic ceramic ferroelectrics show excellent piezoelectric properties, there are serious energy and cost issues. 5 Organic-inorganic hybrid perovskites and crown ether clathrate molecular ferroelectric materials have been widely studied for their advantages of easy processing, high mechanical flexibility and environmental friendliness.…”