Dielectric relaxations and phase-transition-like behavior in SmAlO3 ceramics at high temperatures

Ho-doped sample simultaneously exhibits high-coercivity and enhanced remnant magnetization with a polar R3c symmetry at room temperature. The onset of R3c to Pnma phase transition is observed at high temperatures in the Ho-doped samples.

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VORTICES IN HIGH-TEMPERATURE STRING THEORY

Modern Physics Letters A ◽

10.1142/s0217732389001234 ◽

1989 ◽

Vol 04 (11) ◽

pp. 1063-1067 ◽

Cited By ~ 6

Author(s):

G. CHAPLINE ◽

F.R. KLINKHAMER

Keyword(s):

Phase Transition ◽

Free Energy ◽

High Temperature ◽

String Theory ◽

High Temperatures ◽

World Sheet ◽

Genus Zero ◽

Mass Gap ◽

The World

We discuss the role of XY-like vortices on the world-sheet for the free energy of strings at high temperatures. There is a Kosterlitz-Thouless phase transition at the Hagedorn temperature, above which the vortices contribute to the free energy in genus zero and generate a mass gap. We speculate that high-temperature “string” theory could be essentially discrete.

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Effects of temperature and concentration of La in the form of A1 transverse optical phonon in the PbTiO3 system

Cerâmica ◽

10.1590/s0366-69132012000300006 ◽

2012 ◽

Vol 58 (347) ◽

pp. 313-316 ◽

Cited By ~ 1

Author(s):

M. R. Joya ◽

J. J. Barba-O ◽

P. S. Pizani

Keyword(s):

Phase Transition ◽

Curie Temperature ◽

High Temperatures ◽

Wide Temperature Range ◽

Lead Titanate ◽

Vibrational Mode ◽

Structural Phase ◽

Anomalous Behavior ◽

Effects Of Temperature ◽

Curie Temperature Tc

The structural phase transition from ferroelectric to paraelectric was studied by Raman scattering in the ceramic lead titanate (PbTiO3) doped with lanthanum (La). A1 vibrational mode contains some sub-peaks that have been associated in literature with PbTiO3 concentration (Ca, Ba), and effects of high temperatures as it approaches the Curie temperature (Tc). Raman new study shows that the anomalous behavior of the A1 mode is not only caused by the effects of concentration or temperature near Tc, but by anharmonicity and defects in the network in the PbTiO3 thermodynamically are inevitable. This effect was studied by a wide temperature range from 10 K to Tc in each sample (La = 0, 5, 10, 15, 20%), showing that the effect depends not only on the high temperatures in the pure PT.

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Growth of Acetaminophen Polymorphic Crystals and Solution-Mediated Phase Transition from Trihydrate to Form II in Agarose Gel

Crystals ◽

10.3390/cryst11091069 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1069

Author(s):

Akari Nishigaki ◽

Mihoko Maruyama ◽

Shunichi Tanaka ◽

Hiroshi Y. Yoshikawa ◽

Masayuki Imanishi ◽

...

Keyword(s):

Phase Transition ◽

High Temperatures ◽

Diffusion Rate ◽

Pharmaceutical Compounds ◽

Agarose Gel ◽

Polymorphic Crystals ◽

Fine Morphology

The growth of acetaminophen polymorphic crystals and the solution-mediated phase transition from trihydrate to form II in agarose gel were investigated. The form II crystals grown in gels, presumably because of the agarose content, dissolved less rapidly at high temperatures and were more stable than in water. The trihydrate crystals in the gel were also expected to be stabilized by containing agarose, but in fact the fine morphology resulted in reduced stability. The solution-mediated phase transition from trihydrate to form II via form II seeding took longer in the gel because the gel slowed down the dissolution of the trihydrate by hindering the dispersion of the form II seeds and delayed the growth of form II by reducing the diffusion rate of the molecules dissolved from the trihydrate. Delays in solution-mediated phase transition and changes in stability for crystals grown in gels indicate the effectiveness of gels in controlling polymorphisms in pharmaceutical compounds.

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