Semi‐conductive, Switchable Dielectric and Photoluminescent Properties of Two High‐Temperature Phase Transition Hybrids

Abstract

Bistable switches (electrical switching between "ON" and "OFF" bistable states) have gradually developed into an ideal category of highly intelligent materials, due to their significant applications in optical technology, signal processors, data storage and other switchable media applications in the field of electrical devices. Here, we successfully designed and synthesized4fluoro-phenethylamine; M = Cd (1), Mn (2)), which realized the coupling of thermo-dielectric switching characteristics, semi-conductor characteristics and photo-luminescent properties. DSC (differential scanning calorimetry) and dielectric measurements show that 1 is a sensitive dielectric bistable switch between the high dielectric (ON) and low dielectric (OFF) states. The temperature-variable single crystal structure shows that the both 1 and 2 undergo a high-temperature reversible phase transition around 383 K/380 K, which is caused by the order-disordered transformation of organic cations and the slight distortion of the inorganic framework. In particular, 1 shows outstanding switchable dielectric behavior and semiconducting properties. Further, 1 and 2 emit strong green and yellow luminescence at 527 and 595 nm, respectively.

Ferroelasticity, thermochromism, semi-conductivity, and ferromagnetism in a new layered perovskite: (4-fluorophenethylaminium)2[CuCl4]

“…[21][22][23][26][27][28] In particular, fluorine substitution on phenyl rings has been proved as an effective design strategy to regulate the properties of hybrid materials. [29][30][31][32] Fluorine is the most electronegative element and has a similar van der Waal's radius to that of the hydrogen atom, thus the fluorine substitution usually causes slight structural distortion but significantly tunes or improves the stability and physical properties of materials, 32 e.g., endowing (perfluorobenzylammonium) 2 [PbBr 4 ] and (2-fluorobenzylammonium) 2 [PbCl 4 ] with increased ferroelectric transition temperatures, 31,32 while bringing about a symmetry-reduced room-temperature phase for (FPEA) 2 [MCl 4 ] (M = Cd, Mn, FPEA + = 4-fluorophenethylaminium). 30 On the other hand, many transition metal ions are compatible in layered perovskites, bringing about fascinating properties such as magnetism, fluorescence, and thermochromism.…”

“…21–23,26–28 In particular, fluorine substitution on phenyl rings has been proved as an effective design strategy to regulate the properties of hybrid materials. 29–32 Fluorine is the most electronegative element and has a similar van der Waal's radius to that of the hydrogen atom, thus the fluorine substitution usually causes slight structural distortion but significantly tunes or improves the stability and physical properties of materials, 32 e.g. , endowing (perfluorobenzylammonium) 2 [PbBr 4 ] and (2-fluorobenzylammonium) 2 [PbCl 4 ] with increased ferroelectric transition temperatures, 31,32 while bringing about a symmetry-reduced room-temperature phase for (FPEA) 2 [MCl 4 ] (M = Cd, Mn, FPEA + = 4-fluorophenethylaminium).…”

“…, endowing (perfluorobenzylammonium) 2 [PbBr 4 ] and (2-fluorobenzylammonium) 2 [PbCl 4 ] with increased ferroelectric transition temperatures, 31,32 while bringing about a symmetry-reduced room-temperature phase for (FPEA) 2 [MCl 4 ] (M = Cd, Mn, FPEA + = 4-fluorophenethylaminium). 30…”

Structural phase transition and switchable dielectric behaviour of a one-dimensional chain niobium oxyfluoride

“…Structural phase transition materials have potential application in sensors, and memory and switchable dielectric devices due to their structural diversity and photoelectric physical properties excited under external stimuli, such as temperature, light, and electricity. [11][12][13][14][15][16][17][18][19] All-inorganic structural phase transition materials, such as BaTiO 3 , LiNbO 3 , and Pb(Zr,Ti)O 3 consist of a three-dimensional network by cornersharing MO 6 (M = Ti, Nb, Zr) octahedra with oxygen as a bridging ligand. 20 Organic-inorganic coordination polymers are a large class of structural phase transition materials, 20 in which the bridging ligands are mostly CN − , X − (halide ion), and HCOO − , (N(CN) 2 − ), N 3 − .…”

“…31,32 Compared with allinorganic structural phase transition materials, organicinorganic counterparts possess superior structure flexibility and tunability due to their incorporating organic part. Moreover, they can exhibit some unique properties that allinorganic materials cannot achieve, 11,[33][34][35] such as intrinsic circular-polarizing lens. 36,37 Imidazole has often been used as a cation to prepare organic-inorganic structural phase transition materials owing to its extraordinary molecular motional mechanism.…”