Special Issue "Synthesis and Structural Investigations of Polymorphic Compounds"

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Crystal Engineering".

Deadline for manuscript submissions: closed (30 April 2018)

Special Issue Editors

Guest Editor
Prof. Dr. Arno Pfitzner

Institut für Anorganische Chemie, Universität Regensburg
Website | E-Mail
Guest Editor
PD Dr. Ulrich Schwarz

MPI CPfS, Dresden
Website | E-Mail

Special Issue Information

Dear Colleagues,

In the last two decades, synthesis at extreme conditions and in situ characterization of solid compounds have experienced an enormous gain in both quality and quantity because of extensive progress in radiation sources, detectors, and instrumentation. Especially for the field of innovative materials, variation of thermodynamic state variables, such as pressure or temperature, is a versatile and efficient tool to affect the stability of phases due to the underlying interdependency of crystal structures, and physical, as well as chemical, properties. New and often metastable polymorphs grant access to novel structure property combinations, which are of interest in both fundamental and applied materials science.

In addition, suitable combinations of temperature and pressure open pathways to compounds with previously-inapproachable compositions, due to miscibility gaps or extreme vapor pressure differences. These novel atomic arrangements expand and consolidate our knowledge base on phase diagrams and potential materials. Of interest are inorganic compounds, intermetallic phases, materials, minerals, and pharmaceuticals. Topics include, but are not limited to:

  • In situ synthesis of new compounds and modifications

  • High-pressure high-temperature synthesis of metastable materials

  • Structure and property characterization at extreme conditions, such as pressure, strain, or temperature.

  • Advances in the development of probe heads for the fast in situ detection of phase formation

  • Characterization of polymorphs forming at high-pressure, high-temperature or a combination thereof. Properties under harsh environments, such as corrosive, erosive, high temperature, high pressure, vacuum, low pO2, hard radiation (gamma or neutron), etc.

  • Pressure temperature phase diagrams and their modeling

Prof. Dr. Arno Pfitzner
PD Dr. Ulrich Schwarz
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • high pressure

  • high temperature

  • modeling

  • extreme environments

Published Papers (2 papers)

View options order results:
result details:
Displaying articles 1-2
Export citation of selected articles as:

Research

Open AccessArticle Determination of the Correct Composition of “Hydrous Lead(II) Oxotellurate(IV)” as PbTeO3, Crystallizing as a New Polymorph
Crystals 2018, 8(1), 51; https://doi.org/10.3390/cryst8010051
Received: 21 December 2017 / Revised: 16 January 2018 / Accepted: 17 January 2018 / Published: 19 January 2018
PDF Full-text (3612 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In previous studies, it has been reported that the crystalline product precipitated from the reaction of aqueous solutions of lead(II) salts with sodium oxotellurate(IV) is hydrous lead(II) oxotellurate(IV); however, there have been conflicting specifications of the water content, and the crystal structure of
[...] Read more.
In previous studies, it has been reported that the crystalline product precipitated from the reaction of aqueous solutions of lead(II) salts with sodium oxotellurate(IV) is hydrous lead(II) oxotellurate(IV); however, there have been conflicting specifications of the water content, and the crystal structure of the product is yet undetermined. During the present study, it was shown that the precipitated material does not contain any structural water and in fact represents the third modification (denoted as γ-) of PbTeO3, as revealed by thermal analysis, vibrational spectroscopy, single crystal and powder X-ray diffraction. This modification crystallizes in the space group P 1 ¯ with five formula units in the asymmetric unit, comprising off-centred coordination polyhedra around the PbII cations (coordination numbers: 5–7 with Pb-O distances ranging from 2.3–3.0 Å), and trigonal-pyramidal TeO32− units. The thermal behaviour and structural phase transitions of PbTeO3 were investigated by means of temperature-dependent X-ray powder diffraction and complementary thermal analysis measurements. In addition, the crystal structure of β-PbTeO3 was redetermined, and a comparison was made between the three known polymorphs of PbTeO3. Full article
(This article belongs to the Special Issue Synthesis and Structural Investigations of Polymorphic Compounds)
Figures

Graphical abstract

Open AccessArticle Influence of Alkali Metal Substitution on the Phase Transition Behavior of CsGaQ2 (Q = S, Se)
Crystals 2017, 7(12), 379; https://doi.org/10.3390/cryst7120379
Received: 20 October 2017 / Revised: 27 November 2017 / Accepted: 4 December 2017 / Published: 14 December 2017
Cited by 1 | PDF Full-text (5859 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The formation of solid solution series Cs1−xMxGaQ2-mC64 (M = K, Rb; Q = S, Se; x = 0–1) was studied by X-ray diffraction and spectroscopic methods, revealing a complete miscibility of CsGa
[...] Read more.
The formation of solid solution series Cs1−xMxGaQ2-mC64 (M = K, Rb; Q = S, Se; x = 0–1) was studied by X-ray diffraction and spectroscopic methods, revealing a complete miscibility of CsGaQ2-mC64 with RbGaQ2 and KGaSe2, and a large miscibility gap with KGaS2. All solid solution members exhibit similar Raman spectra, indicating the covalent Ga-Q bonding character. The similar optical band gaps likewise further contribute to this conclusion. Up to a certain degree of substitution, these solid solutions undergo a phase transition similar to CsGaQ2-mC64. The influence of the substitution parameter x on phase transition process was investigated in situ using high-temperature X-ray powder diffraction experiments. Phase-pure solid solutions of the high-temperature polymorphs Cs1−xMxGaQ2-mC16 were obtained up to xmax(K) = 0.1 and xmax(Rb) = 0.3. The crystal structures of these new CsGaQ2-mC16 analogous high-temperature phases were refined from synchrotron diffraction data by Rietveld-refinement. Full article
(This article belongs to the Special Issue Synthesis and Structural Investigations of Polymorphic Compounds)
Figures

Graphical abstract

Back to Top