Special Issue "Non-Ambient Crystallography"

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

Deadline for manuscript submissions: 31 December 2017

Special Issue Editors

Guest Editor
Dr. Edmondo Gilioli

IMEM-CNR, (Institute of Materials for Electronic and Magnetism – National Research Council), Parco Area delle Scienze 37/A - 43124 Parma, Italy
E-Mail
Interests: high Pressure (HP/HT) synthesis; multiferroic materials; superconducting materials; thin film solar cells
Guest Editor
Dr. Francesco Mezzadri

Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A - 43124 Parma, Italy
E-Mail
Interests: crystallography; phase transitions; solid state chemistry; multiferroic materials

Special Issue Information

Dear Colleagues,

Since its birth, crystallography has played a central role in the development of new knowledge, both as a support to other disciplines and in its primary role of revealing the structure of materials, to which most of the properties at the solid state are related. The application of external stimuli (e.g., pressure, temperature, electromagnetic waves, reactive atmosphere, etc.) allows a deeper insight into the behavior of materials in unconventional, in some case extreme, environments, enabling a better understanding of the physics and chemistry of matter in standard conditions.

Nowadays, facilities for the application of non-ambient conditions are easily accessible in many laboratories and an increasing number of studies are unveiling the correlation between the material structure and the external stumuli, both for fundamental research and for practical applications.

The Special Issue on “Non-Ambient Cystallography” aims to gather the innovative achievements of this vast and interdisciplinary community.

Dr. Edmondo Gilioli
Dr. Francesco Mezzadri
Guest Editors

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 1000 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

  • Pressure/Temperature dependent crystallography
  • Experiments under extreme conditions
  • Phase transitions
  • In-situ crystallography
  • Applied electro-magnetic fields

Published Papers

This special issue is now open for submission, see below for planned papers.

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title:Temperature-induced reversible and irreversible transitions between metastable perovskite phases in the BiFe1-yScyO3 solid solutions
Authors: A.N. Salak1, D.D. Khalyavin2, A.V. Pushkarev3, Yu.V. Radyush3, N.M. Olekhnovich3,
A.D. Shilin4, V.V. Rubanik4
1Department of Materials and Ceramic Engineering and CICECO – Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
2ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot, UK
3Scientific-Practical Materials Research Centre of NAS of Belarus, P. Brovka Street, 19, 220072 Minsk, Belarus
4Institute of Technical Acoustics of NAS of Belarus, Lyudnikov Avenue, 13, 210023 Vitebsk, Belarus

Abstract:The antipolar orthorhombic Pnma phase with the 2ap4ap22ap superstructure (ap ~ 4 Å is the pseudocubic perovskite unit-cell parameter) is observed in many perovskite compositions derived from BiFeO3. Temperature-induced structural transformations in metastable perovskite solid solutions with the Pnma structure corresponding to the range of 0.30≤y≤0.60 of the (1-y)BiFeO3-yBiScO3 quasi binary system were studied using temperature x-ray diffraction and neutron powder diffraction. These compositions cannot be prepared in bulk form at ambient pressure but can be stabilized in the Pnma phase by means of quenching after synthesis under high pressure. The compositions were investigated in situ between 1.5 K and the temperature of the stability limit of their metastable phases (about 870-970 K). It has been found that heating of the as-prepared compositions with the Pnma phase leads to formation of the rhombohedral R3c phase (2ap2ap23ap) which either remains on cooling down to room temperature or transforms into polar orthorhombic Ima2 phase (2ap2ap2ap). The observed dependence of temperature of the irreversible Pnma-to-R3c transition on content of scandium in the system is discussed in terms of geometrical factors.

Keywords: metastable phase, high-pressure synthesis, perovskite, polymorphism

 

Title: Combined theoretical and experimental studies on electronic structure, photocatalytic activity, and optical properties of Ga10Ti8O28N2, a new high pressure phase in the GaN-TiO2 system.
Authors: Alwin James1, M. Mahdi Davari Esfahani2, William R. Woerner2, Qiyuan Wu3, Alexandra Sinclair2, Lars Ehm2,4 and John B. Parise1,2,4
1Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
2Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA
3Department of Materials Science & Engineering, Stony Brook University, Stony Brook, NY 11794, USA
4National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA

Abstract: Oxynitrides compounds are a promising class of photocatalyst for solar water splitting. We employed a combination of crystal structure prediction theory (USPEX) and high pressure synthesis, to speed up the discovery of novel oxynitride compounds in the binary system of GaN-TiO2. A new compound, with the composition of Ga10Ti8O28N2, was synthesized at pressure of 1 GPa and temperature of at 1200°C in a piston cylinder apparatus.  Ga10Ti8O28N2 crystallizes in the monoclinic space group C 2/m with the lattice parameters of a=17.758(5) Å, b=2.990(1) Å, c=9.323(3) Å and β=98.44(2)°, with six formula units per unit cell (Z=6). The structure is isomorphous to V2GaO5, with distinct Ti- and Ga-rich blocks with the nitrogen doped sites preferentially occupying the former. The band-gap of Ga10Ti8O28N2 was determined to be 2.96 eV from diffuse reflectance data.

 

Title: Crystallographic determination of the piezoelectric constants in the low temperature quantum paraelectric phase of SrTiO3.

Abstract: SrTiO3 is a widely used crystal, showing a textbook cubic to tetragonal phase transition below 105K. At lower temperatures, a quantum paraelectric phase appears [1], showing gigantic piezoelectric effect [2] with attractive potential applications. We report an x-ray crystallographic study of relevant quantities in the target phase, where low temperature, high electric field and time domain are the three simultaneous challenges to face in order to retrieve the desired microscopic information.

[1] K. A. Mueller and H. Burkard, Phys. Rev. B 19, 3593
[2] D. E. Grupp and A. M. Goldman, Science 276, 392

 

Title:Magnetic structure and short-range spin correlations in multiferroic LuFe2O4 under magnetic field: neutron diffraction study
Authors: Lei Ding1, Fabio Orlandi1, Dmitry D. Khalyavin1, Andrew Boothroyd2, Dharmalingam Prabhakaran2, Geetha Balakhrisnan3 and Pascal Manuel1
1 ISIS Pulsed Neutron Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
2 Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
3 Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
Abstract: We present a detailed study of the magnetic-field effect on the magnetic structure in the charge ordered multiferroic LuFe2O4 through single crystal neutron diffraction. In the absence of a magnetic field, the strong diffuse neutron scattering observed below the Neel temperature indicates that LuFe2O4 shows short-range, two-dimensional (2D) spin correlations in the FeO5 layers, characterized by a development of magnetic scattering rod along the (1/3 1/3 L) direction down to 5 K. We also found for the first time that coupled to the 2D correlations long range order associated with a propagation vector k1=0 set in below 200 K. On the other hand, an external magnetic field applied along the c-axis effectively favours a 3D antiferromagnetic spin ordering between the Fe bilayers evidenced by the increase of the intensity of satellite reflection with propagation vector k2=(1/3 1/3 1/2) whereas it reduces the k1 components and makes the 2D correlations for L=0 incommensurate. Finally, we will discuss the implication of our results in understanding the multiferroic properties of LuFe2O4 in the view of the recent literature.
Keywords: Single crystal neutron diffraction, Magnetic structure, Diffuse scattering, Charge order, Multiferroics

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