Controlling the stability and reactivity of the micro and nanostructured multifunctional materials based on a complex thermodynamic approach
Financed by Ministry of Education and Research
Amount: 1 000 000 Lei
Project coordinator: Dr. Speranta TANASESCU
Coordinating Institution: Institute of Physical Chemistry "Ilie Murgulescu" BUCHAREST
Based on a complex thermodynamic approach, the aim of the project consists in a systematic and rigurous study of the energetic parameters controlling the stability and reactivity of the micro and nanostructured materials and the identification of new routes to control and optimize the properties in the view of specific applications. Some compounds from specific systems were selected for discussion: oxide materials with special electric and magnetic properties Ln1-xAxMn1-yByO3 (Ln=rare earth element; A=alkalin metallic cation, B= tranzitional metal); Ferroelectric materials Ba(Sr)TiO3; Polymorphic phases in micro and nanostructured oxide systems. The solid electrolyte cells measurements (EMF) will be used as experimental technique in order to determine the thermodynamic properties represented by the free energies, enthalpies, entropies, the equilibrium partial pressures of oxygen. By coupling the EMF measurements with the solid state coulometric titration technique, investigation of the nonstoichiometric compounds whose properties are higly sensitive to deviations from stoichiometry can be done. The enthalpies of the phase transitions will be measured by DSC. The following elements of novelty and originality of the project are evidenced:- the identification of new micro and nanostructured materials with special electric and magnetic properties;- the study of the nonstoichiometry effect on the thermodynamic properties in the temperature ranges and pressure of oxygen domains usually used in applications;- the effect of particle on the stability and energetics of the oxide phases, the reevaluation of the phase diagrams in the nanostructured systems. The results will be used to find new routes to change the properties of the multifunctional materials.