Impedance spectroscopy of distinct electrical responses in TlH2PO4

Abstract

The ferroelastic phase in hydrogen-bonded TlH2PO4 was investigated by means of impedance spectroscopy. The high-temperature dielectric susceptibility revealed the corresponding Curie-Weiss temperature to be far above the antiferroelectric phase transition temperature, and a phase boundary has been identified and confirmed by the distinct electric field dependencies of the polarization.

Recombination zone study of phosphorescent organic light-emitting diodes with triplet mixed host emitting structure

“…Recombination zone of phosphorescent organic light-emitting diodes (PHOLEDs) was studied using a graded doping structure in EML and it was found that recombination zone of green PHOLEDs was very close to hole transport layer (HTL) [2]. Another work about the recombination zone of OLED was carried out by Kalinowski et al and they changed the thickness of emitting layer to study the recombination zone of OLEDs [7].…”

“…2. Device I has Ir(pq) 2 acac near HTL and device II has Ir(pq) 2 acac at the center of EML, while device III has Ir(pq) 2 Recombination zone of green phosphorescent organic light-emitting diodes (PHOLEDs) with triplet mixed host was studied using red sensing layer. Recombination zone of triplet mixed host device with 4,4 0 ,4 00 -tris(N-carbazolyl)triphenylamine and 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene as hosts was rather dispersed compared with that of single host device with recombination zone near charge transport layer.…”

“…In addition to charge balance, recombination zone of holes and electrons is critical to lightemitting efficiency of OLEDs [2]. The recombination zone affects charge injection, exciton quenching effect and optical properties of devices [2][3][4][5].…”

Impedance spectroscopy of the superprotonic conduction in LiH2PO4

“…[18][19][20] Dielectric relaxation can be quite useful for the study of charge dynamics, and impedance spectroscopy of LDP has in this work provided us with an opportunity to study the nature of the superprotonic conduction. 21,22 LDP polycrystalline powder (99.99%), purchased from Aldrich and dried for 3 h at 80 C, was fabricated into a disk sample (12-mm diameter, 1.2-mm thickness) by uniaxially pressing in a cylindrical die at 4000 kg/cm 2 . The complex impedance measurements were made on the pellet sample as a function of temperature in a frequency range from 10 Hz to 2 MHz by using a Quadtech 7600 impedance analyzer.…”

Phase Diagram of TlH2(P1-xAsx)O4Mixed Crystals

“…20) Moreover, the mixed phase with coexisting antiferroelectricity and paraelectricity was insisted below 327 K (T s ) in the ferroelastic phase of TlH 2 PO 4 . 21,22) Mixed crystals of the KH 2 PO 4 family have been investigated by many researchers. The substitution of cations, between ferroelectric RbH 2 PO 4 and antiferroelectric NH 4 H 2 PO 4 generates the dipole glass state at low temperatures.…”