OXYHALIDE MATERIALS · Synthesis, Raman scattering and infra-red spectroscopy investigations of correlated behaviour in transition metal oxyhalides
6РП — Действия „Мария Кюри“
- Период
- 2004-03-01 → 2006-02-28
- Финансиране от ЕС
- 158 017 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите.
Накратко на български
Оксихалидните материали, като например Cd2Re2O7, се анализират чрез лазерна спектроскопия, за да се разберат техните структурни и магнитни свойства. Това помага за обяснението на процесите, при които електроните се движат без съпротивление, превръщайки материала в свръхпроводник.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - OXYHALIDE MATERIALS (Synthesis, Raman scattering and infra-red spectroscopy investigations of correlated behaviour in transition metal oxyhalides)
The aim of the project was to study the structure and properties of magnetically and electrically active materials using Raman and infra-red spectroscopy techniques. The Intra-European Marie Curie fellowship allowed the recipient to move country and join the Condensed Matter Physics group at Chalmers University of Technology, Gothenburg, Sweden and undertake training through research. In particular an important objective of the project was training in Raman spectroscopy. The researcher made the materials in the department of Chemistry before performing the Raman measurements in the Physics department. Raman spectroscopy is a simple technique in principle. A laser light is shined onto the surface of the material and the light can interact with excitations such as vibrations in the material and lose or gain energy from these interactions. By studying these changes in the energy of the scattered light information about the structure and also magnetic properties of the sample can be obtained. The most important scientific achievement made during the project was the characterisation of the structural changes that occur in the material Cd2Re2O7 on cooling it from room temperature to 10 K using Raman spectroscopy. On further cooling, to 1 K (-272 Degrees Celsius), this material becomes a superconductor, i.e. electrons can move in the material without any resistance. Understanding the structural behaviour of the material is vital to understand this property and our results allowed the first model explaining the structural changes to be developed. Another highlight of the project was the discovery of new materials of the form Sr1-xBixCoO3-y (0.1 x 0.2), e.g. Sr0.85Bi0.15CoO2.7. These materials have interesting structures made up of layers of CoO6 octahedra and CoO4 tetrahedra and when treated with oxygen gas they can absorb it and change structure.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
A range of first row transition metal ox halide materials with structures closely related to the layered parasite Huddleston-Popper series of significance to high Tic cuprites and CMR magnates are to be investigated. In particular magnetic and electronic interactions within manganese, iron, cobalt and copper containing systems will be studied using Raman scattering and Infra-red (IR) spectroscopy to gain a better understanding of the mechanisms that govern correlated behaviour. The materials offer the potential to control transition metal oxidation state through variation of the halide to oxide ratio and also inter and intra-layer metal to metal separations through choice of the halide ion, i.e. Fuqua; Aliquot; Briquette; The dimensionality of the systems also varies from single metal-oxide layer K2NiP4-type materials through to double and triple layer compounds with increasing three-dimensional character. The ability to influence these factors makes them ideal for in-depth studies probing correlated behaviour. The ant ferromagnetic transitions within the materials will be characterised using variable temperature Raman and IR techniques to reveal information on local structural effects and charge carrier delocalisation as Kneel is crossed. Systematic studies on structurally analogous series will allow the identification of effects specific to transition metal, e.g. John-Teller interactions, to be determined. The impact of changing halide size on exchange pathways and consequently the strength and type of magnetic correlation will also be studied. The experiments will be performed on high quality polycrystalline and single crystal samples, which are to be synthesised as part of the interdisciplinary project. The synthetic programme will also aim to prepare new ox halide materials with enhanced properties by introducing additional charge carriers into the systems via variation of the halide: oxide ratio and A-site action substitution.
Оригинален текст от CORDIS (на английски).
Участници
- CHALMERS TEKNISKA HOGSKOLA AB · GOTHENBURGКоординаторШвеция
Връзки
Данни: CORDIS, © Европейски съюз