CARPATH

Exploring critical conditions as a new tool for enhancing electrocaloric properties of Ba-based lead free ceramics (CritEC)

Project code: PN-III-P1-1.1-TE-2019-1689
Project number: TE1/25.08.2020
Funded by the Executive Unit for Financing High Education, Research, Development and Innovation, CNCS – UEFISCDI

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Study and multiscale modeling of new ferroelectric oxides – NOVOXFER

Financed by the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project PN-III-P3-3.1-PM-RO-FR-2019-0069

The major objective of this project is to create an active collaboration between two groups of researchers with complementary knowledge (physicists, chemists) and experimental facilities: a group from "Al. I. Cuza" University of Iasi, Romania (UAIC) and the group from Univ. D'Artois, Lens, France (UCCS). The aim is to investigate in a synergic and multidisciplinary way through experimental activities from nanoscale to macro-scale and using modeling approach a topic of high actuality, namely, a complex study of the structural, dielectric, ferro- and piezoelectric properties of new classes of lead-free oxides with potential applications in the field of conversion, storage and energy recovery. The proposed systems for this study are: (i) A₂WO₆ class (A = lanthanides Ln³⁺ or Bi³⁺), in which ferroelectricity has not been confirmed up to date except at nanoscale and only in thin films; (ii) BaTiO₃- based binary and ternary solutions: (Ba,Ca)(Ti,M)O₃ (M = Zr⁴⁺, Sn⁴⁺, Ce⁴⁺), where it is expected to generate extraordinary properties (pyro-, piezo-, ferroelectricity, tunability, giant permittivity) in the range of concentrations for which there is a coexistance of polymorphs. The main expected results are: reciprocal extension of knowledge and scientific competences through bilateral visits and active collaboration, investigation of new classes of ferroelectrics, valuable publications in the proposed topics, creating the premises for future joint participation to other international projects.

Project achievements (2019-2020)

Project achievements (2021)

 

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Studiul si modelarea multi-scala a unor oxizi feroelectrici noi – NOVOXFER

Cod proiect: PN-III-P3-3.1-PM-RO-FR-2019-0069
Domeniul științific: 4. Eco-nanotehnologii si materiale avansate. 4.3. Materiale avansate
Durata contractului: 18 luni
Valoare: 25.035,00 lei

Obiectivul proiectului este de a crea un cadru de colaborare activă între două grupuri de cercetători având cunoştinţe şi facilităţi experimentale complementare: grupul de fizicieni din România (Univ. “Al. I. Cuza” din Iaşi: UAIC) şi cel de chimişti din Franţa (Univ. d’Artois, Lens: UCCS). Scopul este de a aborda în mod sinergic şi multidisciplinar prin activităţi experimentale de la scală nanometrică la macro-scală şi prin modelare teoretică o tematică de mare actualitate, şi anume, un studiu complex al proprietăţilor structurale, dielectrice, fero- şi piezoelectrice ale unor noi clase de oxizi fără plumb, cu potenţial aplicativ în domeniul conversiei, stocării şi recuperării de energie. Sistemele propuse pentru studiu sunt: (i) A₂WO₆ (A = lantanide Ln³⁺ sau Bi³⁺), în care nu a fost confirmată până în prezent feroelectricitatea decât la nanoscală şi doar în filme subțiri; (ii) soluţii solide binare şi ternare pe bază de BaTiO₃: (Ba,Ca)(Ti,M)O₃ (M = Zr⁴⁺, Sn⁴⁺, Ce⁴⁺), în care se aşteaptă proprietăţi extraordinare (pyro-, piezo-, feroelectrice, tunabilitate, permitivitate superioară) în domeniul de concentraţii pentru care există o superpoziție de faze structurale. Principalele rezultate aşteptate sunt: extinderea reciprocă a cunoaşterii şi competenţelor ştiinţifice prin vizite bilaterale şi colaborare activă, investigarea unei noi clase de feroelectrici, publicaţii valoroase în tematica proiectului, viitoare participări în comun la proiecte finanţate din alte surse.

Obiective:

ETAPA I (2019)

Prepararea si caracterizarea structurala, microstructurala si electrica a compusilor soluții solide binare/ternare cu formula (Ba,Ca)(M,Ti)O₃ (M = Zr⁴⁺, Sn⁴⁺, Ce⁴⁺)

ETAPA a II a (2020)

Caracterizare dielectrica si feroelectrica a compusilor de tip A₂WO₆ (A = lantanidă Ln³⁺, Bi³⁺) si a soluțiilor solide binare/ternare (Ba,Ca)(M,Ti)O₃ (M = Zr⁴⁺, Sn⁴⁺, Ce⁴⁺)

 

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Microwave behavior study on non-saturated magnetic nanowire systems

Financed by the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project   PN-II-RU-TE-2012-3-0449, no. 26 / 2013

 

Director of proiect:
Lect.dr.Ioan DUMITRU
(Faculty of Physics, Alexandru Ioan Cuza University, Iaşi)

The project is dedicated to the study of fundamental properties of nanostructured magnetic materials with the aim to evidence possibilities of their use in microwave devices.

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The Modelling of Photoinduced Phase Transitions in Anisotropic Media – MoPhaPho

Financed by the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project PN-III-3BM/2019

The research project described in the proposal will be conducted by investigators at the Excellence Center for Applied Research in Physics and Advanced Technologies (CARPATH) of the Faculty of Physics, “Alexandru Ioan Cuza” University (UAIC) from Iasi, Romania, and University of Rennes 1, France. This project will mix the expertise of the Collet group at IPR for photoinduced phase transition and ultrafast experimental studies and the expertise of the Enachescu group for modelling elastic coupling associated with these cooperative effects. These teams have complementary expertise: the group of University of Rennes 1 is one of the most important in the world with unique experimental facilities for the study of femtosecond phenomena in molecular materials, while the physicists at UAIC are internationally renowned for their models elaborated in order to characterize both spin crossover and magnetic materials and equally proposed new methods to analyze experimental data. The cooperation between the members of Rennes team and members of CARPATH started in 2012 and has been concretised up to now in a recent paper published in Nature Materials, at the heart of the present project.

Thanks to remarkable development of ultrafast techniques, operating on time scales faster than atomic motions or material reorganizations, new opportunities have emerged to impact the macroscopic state of a material, and thereby change its physical properties. Several experiments at the cutting edge of the laser and X-ray technologies have provided essential insights into real-time transformations of diverse materials, from the melting of charge and/or spin order in electron correlated systems to molecular switching in the solid state. Contrary to coherent optical phonons long under scrutiny, coherently propagating cell deformations over acoustic time-scale, have not benefited from the same surge of effort, in particular when the crystalline medium exerts positive feedback on the constituents. A severe limitation to photoinduced transformations triggered by a femtosecond laser pulse is their transient nature. A vast majority of reported experiments point to fast relaxation of excited electronic state and induced rearrangements of atoms inside unit cell, as factors prohibiting stabilisation. It is of paramount importance from the fundamental stand point, as well as for the control of non-volatile information, to explore whether induced crystal deformations have capacity to extend the lifetime of photoinduced states.

The goal of this project is to address the issue of the switching of materials by light pulse from the perspective of elastic cooperativity, notwithstanding its common perception related to electrons and optical phonons, we choose in this project to focus on spin-crossover systems where the phase transitions are driven by elastic interactions due to the swelling of photoswitched molecules.

 

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