Ferroelectricity in the dimethylaminaluminiumsulphate crystal

Kirpichnikova, L. F.; Shuvalov, L. A.; Ivanov, N. R.; Prasolov, B. N.; Andreyev, E. F.

doi:10.1080/00150198908216791

Cited by 55 publications

(36 citation statements)

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“…So far, this subfamily consists of two crystahs, namely: DMAAS -(CΗ 3 ) 2 ΝΗ 2 Αl(SO4 ) 6 . 6H2O and DMAGaS -(CR3 ) 2 ΝΗ 2 Ga(SO 4) 6 .6Η2O [1][2][3]. DMAAS undergoes continuous para-ferroelectric phase transition of Τc = 153 I{ and DMAGaS undergoes two successive phase transitions at Τc 1 = 136 I{ and at Tc2 = 118 K [4,5].…”

Section: Introductionmentioning

confidence: 99%

Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

Czapla

Tchukvinskyi

1998

Acta Phys. Pol. A

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The paper presents the new data of dielectric dispersion in DMAGaS crystal. The very pronounced dispersion above T c1 = 136 K is observed in the frequency range 100 Ηz-30 MHz with a single relaxation process. The relaxation time τ of an electric dipole reaches 2.17 x 10 -7 s at the T, 1 . The activation free energy ΔF of the dipoles is estimated to be equal to 0.087 eV. The order-disorder type of phase transition is confirmed.

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Section: Introductionmentioning

confidence: 99%

Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

Czapla

Tchukvinskyi

1998

Acta Phys. Pol. A

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“…The nature of ferroelectric and ferroelastic phases has been drawn from the investigations of dielectric [2][3][4], birefringence [2,5], dilatometric [6], piroelectric [7], electro-and piezooptic [8] properties of DMAAS. Temperature dependencies of (409) refractive indices of DMAAS in the range of ferroelectric phase transition have not been investigated till now.…”

Section: Introductionmentioning

confidence: 99%

“…Crystal of dimethylammonium aluminium sulphate hexahydrate (CH 3 ) 2 NH 2 A1(SO4 ) 2 .6H 2 O (DMAAS) has been widely studied recently by different experimental methods [1][2][3][4][5][6][7][8]. It undergoes ferroelectric phase transition (PT) of second order 2/m → 171 at = 150 K. The transition is associated with ordermg of DMA cations when instead of four bonds averaged in time only two more strong N-H...O bonds appear.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 1999

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Experimental investigation of the thermal linear expansion 1(T) and temperature dependencies of the interference optical path difference D(T) were carried out for (CH 3 )2 NH2Al(SO 4 )2 • 6H2O crystal, in the range of 120-310 K for three crystal physical directions. Decrease in electrostriction coefficients g of crystal was observed on approaching the phase transition point Tc 150 K in ferroelectric phase. Relative temperature changes of the lengthening 51/1 and refractive index δn/(n -1) are of the same order of magnitude. Peculiarities of temperature dependence of dilatometric and optical parameters of (CH3)2NH2Al(SO4)2.6112O testify for qualitative reconstruction of chemical bonds in the crystal when temperature changes in the same phase.

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“…Crystals of DMAAS and DMAGaS were widely studied with different experimental methods [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. In particular, the magnetic resonance methods have already been employed in studies of the phase transitions in both systems [9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

“…The crystal structure of dimethylammonium gallium sulfate hexahydrate (DMAGaS) (CH 3 ) 2 NH 2 Ga(SO 4 ) 2 · 6H 2 O and the isomorphic dimethylammonium aluminium sulfate hexahydrate (DMAAS) is built up of Ga or Al cations coordinating six water molecules, regular SO 4 tetrahedra and [(CH 3 ) 2 NH 2 ] + (DMA) cations, all hydrogen bonded to a three-dimensional framework [1][2][3][4]. Both crystals are ferroelastic in the paraelectric phase and showing the monoclinic space (283) group P 2 1 /n.…”

Section: Introductionmentioning

confidence: 99%

EPR Study of the Phase Transition in Dimethylammonium Gallium Sulfate Hexahydrate

2005

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X-band electron paramagnetic resonance investigations of single crystals of Cr3+ -doped dimethylammonium gallium sulphate hexahydrate are presented from room temperature down to 110 K. The crystal undergoes a order-disorder phase transition to ferroelectric phase at 134 K and additionally a first-order transition into a low temperature non-ferroelectric phase at T c2 = 116 K. The spin-Hamiltonian parameters were determined for paraelectric and ferroelectric phases. The spin-Hamiltonian parameters in the paraelectric phase are: g = 1.982 ± 0.002, b 0 2 = (890 ± 10) × 10 −4 cm −1 , b = (386 ± 15) × 10 −4 cm −1 . Remarkable EPR line width changes confirm the order-disorder character of the ferroelectric phase transition. Additionally observed triplet lines demonstrate freezing-out of dimethylammonium reorientations which can be considered as a prime reason for this transition similarly as observed in dimethylammonium aluminium sulfate hexahydrate.

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Ferroelectricity in the dimethylaminaluminiumsulphate crystal

Cited by 55 publications

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Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

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

EPR Study of the Phase Transition in Dimethylammonium Gallium Sulfate Hexahydrate

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Ferroelectricity in the dimethylaminaluminiumsulphate crystal

Cited by 55 publications

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Dielectric Dispersion Studies in (CH3)2NH2Ga(SO4)2- 6H2O(DMAGaS) Crystal

Dielectric Dispersion Studies in (CH3)2NH2Ga(SO4)2- 6H2O(DMAGaS) Crystal

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

EPR Study of the Phase Transition in Dimethylammonium Gallium Sulfate Hexahydrate

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Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

Dielectric Dispersion Studies in (CH₃)₂NH₂Ga(SO₄)₂- 6H₂O(DMAGaS) Crystal

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