Dielectric properties of NH₂(CH₃)₂AL(SO₄)₂· 6H₂O crystals at low temperatures

Optical and Dilatometric Properties of (CH3)2NH2Al(SO4)2·6H2O Crystals in Paraelectric and Ferroelectric Phases

“…2). Similar anomaly was observed here on the temperature dependencies of dielectric loss tangent tan δ(T) [11] and was explained by the formation of some new domain structure or diminishing space regions of correlated dipoles caused by "freezing" of H-bonds under an influence of spontaneous polarization. On the basis of data presented in Fig.…”

Phase Transitions and Fundamental Ferroelectric Dispersion in DMAAl1-xCrxS Crystals

“…In [3,6] The nitrogen vapor ow cryostat with UNIPAN 680 temperature control system was used for the dielectric measurements. The temperature was stabilized with an accuracy not worse than 5 × 10…”

THERMODYNAMICS AND DIELECTRIC ANOMALIES OF DMAAS AND DMAGaS CRYSTALS IN THE REGION OF PHASE TRANSITIONS (LANDAU THEORY APPROACH)

“…The majority of the performed measurements is devoted to the longitudinal dielectric permittivity ε x (or its real part ε ′ x for low frequency alternating current measurements) mainly in the region of the high-temperature phase transition for DMAGaS and the corresponding phase transition in DMAAS. Such data are reported in the works [5,8,9,11] (DMAGaS) and [4,7,8] (DMAAS); only in the paper [7] the temperature behaviour of all permittivity components (ε ′ a , ε ′ b , ε ′ c ) for DMAAS crystal in the wide range of temperatures (from ≃ 90 K to ≃ 280 K) was measured. In some papers the dependence of spontaneous polarization on temperature in the ferroelectric phase was investigated and coercivity fields were measured [8,9] (the value of P s in the state close to saturation is about 1.4-1.9 C/m 2 for DMAAS and 0.9-2.0 C/m 2 for DMAGaS).…”

“…A set of structural [1][2][3], dilatometric, dielectric, pyroelectric and ultrasonic [4][5][6][7][8][9][10][11][12] measurements is made for considered systems, which allows us to establish their main dielectric, mechanical and dynamical characteristics (see below). At the same time these investigations are incomplete and of preliminary stage in many directions.…”