scholarly journals Macroscopic behavior of the distorted A and B phases and the polar phase of superfluid He3 in an anisotropic aerogel

2020 ◽  
Vol 102 (9) ◽  
Author(s):  
Helmut R. Brand ◽  
Harald Pleiner
Keyword(s):  
Polar Phase ◽  
Macroscopic Behavior

Extraction of hafnium(IV) with N-benzoyl-N-phenylhydroxylamine solutions from strongly acid solutions containing dimethyl sulphoxide or hexamethylphosphor triamine

1984 ◽  
Vol 49 (10) ◽  
pp. 2205-2209
Author(s):  
Jiří Příhoda ◽  
Alois Zeman
Keyword(s):  
Ion Exchange ◽  
Dimethyl Sulfoxide ◽  
Dimethyl Sulphoxide ◽  
Polar Phase ◽  
Acid Solutions ◽  
Extraction Mechanism

The extraction of hafnium(IV) with N-benzoyl-N-phenylhydroxylamine solutions in chloroform or toluene from strongly acid (HClO4) solutions of dimethyl sulfoxide or hexamethylphosphor triamide has been studied. These substances were found to suppress the conversion of the extraction mechanism from ion exchange to solvation: while in solutions free of these substances this conversion takes place at HClO4 concentrations of about 4 mol l-1, in the mixed aqueous-organic (polar) phase the requisite acid concentrations are considerably higher. The possible causes of this effect are discussed.

scholarly journals Stabilization of Ferroelectric Phase in Highly Oriented Quinuclidinium Perrhenate (HQReO4) Thin Films

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2126
Author(s):  
Junyoung Lee ◽  
Woojun Seol ◽  
Gopinathan Anoop ◽  
Shibnath Samanta ◽  
Sanjith Unithrattil ◽  
...  
Keyword(s):  
Thin Films ◽  
Solution Process ◽  
Intermediate Temperature ◽  
Perovskite Oxide ◽  
Temperature Phase ◽  
Polar Phase ◽  
Practical Applications ◽  
Temperature Range ◽  
Potential Alternative ◽  
Temperature Window

The low-temperature processability of molecular ferroelectric (FE) crystals makes them a potential alternative for perovskite oxide-based ferroelectric thin films. Quinuclidinium perrhenate (HQReO4) is one such molecular FE crystal that exhibits ferroelectricity when crystallized in an intermediate temperature phase (ITP). However, bulk HQReO4 crystals exhibit ferroelectricity only for a narrow temperature window (22 K), above and below which the polar phase transforms to a non-FE phase. The FE phase or ITP of HQReO4 should be stabilized in a much wider temperature range for practical applications. Here, to stabilize the FE phase (ITP) in a wider temperature range, highly oriented thin films of HQReO4 were prepared using a simple solution process. A slow evaporation method was adapted for drying the HQReO4 thin films to control the morphology and the temperature window. The temperature window of the intermediate temperature FE phase was successfully widened up to 35 K by merely varying the film drying temperature between 333 and 353 K. The strategy of stabilizing the FE phase in a wider temperature range can be adapted to other molecular FE materials to realize flexible electronic devices.

Macroscopic behavior of a quantum monomode laser

1976 ◽  
Vol 14 (5) ◽  
pp. 399-416 ◽  
Author(s):  
D. Walgraef
Keyword(s):  
Macroscopic Behavior

scholarly journals Interactions of Ruddlesden-Popper Phases and Migration-Induced Field-Stabilized Polar Phase in Strontium Titanate

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 693
Author(s):  
Christian Ludt ◽  
Elena Ovchinnikova ◽  
Anton Kulikov ◽  
Dmitri Novikov ◽  
Sibylle Gemming ◽  
...  
Keyword(s):  
Strontium Titanate ◽  
Density Functional ◽  
Surface Region ◽  
Point Of View ◽  
Polar Phase ◽  
Near Surface ◽  
Atomic Displacements ◽  
Induced Field ◽  
And Migration ◽  
Novel Concept

This work focuses on the validation of a possible connection of the known Ruddlesden-Popper (RP) phases and the novel concept of the migration-induced field-stabilized polar (MFP) phase. To study this subject, model structures of RP phases in bulk strontium titanate are analyzed by means of density functional theory (DFT). The obtained geometries are compared to experimental MFP data. Good agreement can be found concerning atomic displacements in the pm range and lattice strain inferred by the RP phases. Looking at the energy point of view, the defect structures are on the convex hull of the Gibb’s free energy. Although the dynamics to form the discussed defect models are not addressed in detail, the interplay and stability of the described defect model will add to the possible structure scenarios within the near-surface region of strontium titanate. As a result, it can be suggested that RP phases generally favor the MFP formation.

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