scholarly journals Ferroelectricity and Phase Transitions in Pyridinium Periodate Single Crystal

2000 ◽  
Vol 55 (11-12) ◽  
pp. 891-894 ◽  
Author(s):  
Z. Czapla ◽  
S. Dacko ◽  
B. Kosturek
Keyword(s):  
Phase Transitions ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Phase Ii ◽  
Ferroelectric Phase ◽  
Hysteresis Loops ◽  
Electric Permittivity ◽  
Phase Ii And Iii ◽  
Three Phases

Abstract Single crystals of pyridinium periodate were grown, and their physical properties were studied. Anomalies of the electric permittivity and birefringence were observed at TC1 = 321 K and TC2 = 211 K. These observations gave evidences for the existence of three phases denoted as I, II, and III. Hysteresis loops were observed both in phase II and III. Pyroelectric measurements showed two anomalies at TC1 and TC2 . The anomaly at TC1 is related to the transition between a para-and ferroelectric phase, and the anomaly at T cl to the transition between two ferroelectric phases.

Effective symmetry and physical properties of twinned perovskite ferroelectric single crystals

2001 ◽  
Vol 16 (2) ◽  
pp. 570-577 ◽  
Author(s):  
Jiří Erhart ◽  
Wenwu Cao
Keyword(s):  
Phase Transitions ◽  
Physical Properties ◽  
Single Crystals ◽  
Material Properties ◽  
Domain Walls ◽  
Ferroelectric Phase ◽  
Twin Structure ◽  
Twin System ◽  
Property Changes ◽  
Ferroelectric Phase Transitions

The effective symmetry and material properties of twinned ferroelectric crystals with perovskite structure were analyzed. The twins or twinbands studied here were formed during ferroelectric phase transitions, which resulted in one of the following symmetry changes: m3m → 3m, m3m → 4mm, and m3m → mm2. It was found that the volume ratios of the two domains in a twin structure were not always equal due to the existence of defect pinning to the domain walls. This unequal partition changed the effective symmetry; hence, the effective macroscopic physical properties of the twin system. Using the data of LiNbO3, BaTiO3, and KNbO3, a detailed analysis has been carried out on macroscopic material property changes caused by the deviation from equal domain volume partition for crystals having 3m, 4mm, and mm2 symmetries.

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

Ferroelectric phase transitions in CsLiMoO4 single crystals

1981 ◽  
Vol 67 (2) ◽  
pp. 377-380 ◽  
Author(s):  
K. S. Aleksandrov ◽  
A. T. Anistratov ◽  
S. V. Melnikova ◽  
P. V. Klevtsov ◽  
A. I. Kruglik ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Single Crystals ◽  
Ferroelectric Phase ◽  
Ferroelectric Phase Transitions

Physical properties and phase transitions of bis(guanidinium)zirconium bis(nitrilotriacetate)hydrate, [C(NH2)3]2Zr[N(CH2COO)3]2 · H2O

1997 ◽  
Vol 212 (11) ◽  
Author(s):  
E. Haussühl ◽  
E. Tillmanns
Keyword(s):  
Thermal Expansion ◽  
Phase Transitions ◽  
Physical Properties ◽  
Single Crystals ◽  
Optical Quality ◽  
Refractive Indices ◽  
Strong Anisotropy ◽  
Ultrasonic Methods ◽  
Piezoelectric Constants

AbstractLarge single crystals of optical quality of bis(guanidinium)zirconium bis(nitrilotriacetate)hydrate have been grown from aqueous solutions. Complete elastic, thermoelastic and piezoelastic tensors have been determined by ultrasonic methods. In addition, the tensor of thermal expansion, refractive indices, dielectric and piezoelectric constants have been studied in the range between 210 K and 330 K. Most physical properties investigated show a strong anisotropy. The piezoelectric constant

scholarly journals Magnetocaloric properties of the single crystal Mn0.99Fe0.01As

2019 ◽  
Vol 55 (1) ◽  
pp. 118-124
Author(s):  
G. A. Govor ◽  
A. O. Larin ◽  
V. I. Mitsiuk ◽  
G. S. Rimskiy ◽  
T. M. Tkachenkа
Keyword(s):  
Magnetic Field ◽  
Crystal Structure ◽  
Phase Transition ◽  
Phase Transitions ◽  
External Magnetic Field ◽  
Single Crystal ◽  
Single Crystals ◽  
Calculation Method ◽  
Magnetostructural Transition ◽  
Magnetocaloric Properties

The Stockbargard – Bridgman method yielded single crystals Mn0.99Fe0.01As. The effect of an external magnetic field with an intensity of up to 10 T on phase transitions in the single crystal Mn0.99Fe0.01As is studied. It is established that the magnetostructural phase transition in Mn0.99Fe0.01As is accompanied by a change in the entropy ΔSm, which is due to the transformation of the crystal structure. At temperatures above the temperature of the magnetostructural transition Tu = 290 K, the existence of an unstable magnetic structure is obtained. The magnetocaloric characteristics of the material under study are determined by an indirect calculation method based on the Maxwell thermodynamic relations and the Clapeyron – Clausius equation.

Structure of tetrakis(dimethylamino)ethene (TDAE) at low temperatures

1995 ◽  
Vol 210 (7) ◽  
Author(s):  
J. Bruckmann ◽  
C. Krüger ◽  
H. Borrmann ◽  
A. Simon ◽  
H. Bock
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Low Temperatures ◽  
Structure Refinement ◽  
Static Disorder ◽  
Structural Details ◽  
Different Temperatures

AbstractThe single crystal structure of TDAE was redetermined at different temperatures. Phase transitions are observed by warming the samples from low temperatures but never by cooling. Due to this special behavior it was possible to cool single crystals to 90 K. The data collected from such supercooled crystals resulted in a more precise and reliable structure refinement. Interesting structural details of the sterically overcrowded molecule are elucidated. The temperature dependence of the distortions of the nonplanar dimethylamino groups indicates dynamic behavior rather than static disorder.

Single crystal growth and physical properties of dolerophanite single crystals

2019 ◽  
Vol 3 (12) ◽  
Author(s):  
L. Zhao ◽  
C. Dalton ◽  
S.-C. Liao ◽  
Z. Hu ◽  
H.-J. Lin ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Single Crystal Growth

scholarly journals Orbital Order and Structural Phase Transitions in Vanadium Spinel FeV2O4

2014 ◽  
Vol 70 (a1) ◽  
pp. C1358-C1358
Author(s):  
Shogo Kawaguchi ◽  
Hiroki Ishibashi ◽  
Shigeo Mori ◽  
Jungeun Kim ◽  
Kenichi Kato ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Physical Properties ◽  
Single Crystal ◽  
Degrees Of Freedom ◽  
Structural Phase ◽  
Mode Analysis ◽  
Structural Transitions ◽  
Orbital Order ◽  
Orbital State ◽  
Powder Samples

Orbital degrees of freedom plays an important role in condensed matter physics because it is strongly related with phase transitions and induces the fascinating physical properties. A spinel oxide FeV2O4is one of the peculiar examples because this compound has double orbital degrees of freedom at both Fe2+and V3+ions. Furthermore, this material represents exotic physical properties [1,2], i.e.; multiferroic, large magnetostriction, and successive structural transitions with decreasing temperature: cubic - tetragonal (c < a: tetraHT, 138K) - orthorhombic (orthoHT, 108 K) - tetragonal (c > a: tetraLT, 68 K). However, the origin of structural transitions and physical properties is controversial until now. In order to clarify the origin, we have performed synchrotron x-ray diffraction experiments at low temperatures at beamline BL02B2 (for the powder samples) in SPring-8 and BL-4C (for the single crystal) of the Photon Factory, KEK. Furthermore, we have carried out the magnetization and the specific heat measurements using polycrystalline samples and single crystal of FeV2O4. We have firstly found another orthorhombic phase (orthoLT) below 30 K in the polycrystalline sample of FeV2O4, shown in figure 1. The Rietveld analysis was performed, and the overall qualities of fittings were fairly good. In order to investigate the details of the orbital state of Fe2+and V3+in FeV2O4, we have performed the normal mode analysis, which is based on static displacements of the tetrahedron of FeO4and octahedron of VO6. In the orthoLT phase, we found the orbital order of Fe2+ions, which is mixture of 3z2-r2and y2-z2orbitals, without change of orbital order of V3+ions. This result indicates that the origin of the orthoLT phase is derived from the competition between cooperative Jahn-Teller effect and relativistic spin-orbit coupling of Fe2+ions. We also discuss the origins of the other phase transitions considering the orbital state of V3+and Fe2+ions, and then the orbital dilution effect, where the structural and magnetic properties are investigated by using powder samples substituted for Fe2+and V3+ions by other ions (Mn2+and Fe3+) with no orbital degrees of freedom.

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