Speaker
Vítor Amaral
(Departamento de Física e CICECO, Universidade de Aveiro)
Description
The search for new systems that exhibit simultaneous ferroelectric and ferromagnetic orders have recently motivated Physic and Materials Science scientific communities to a meticulous research, that beyond searching the simultaneous electric and magnetic orders also have as an objective the maximization of its coupling. These materials offer the possibility to manipulate electrically the magnetic degrees freedom or vice-versa [1-2].
Recently, AgCrO2 delafossite has been reported as another multiferroic material [3]. Also, a correlation between the electric dipoles and the magnetic structure of this system has been claimed.
In such compounds local distortions have a fundamental influence in the ferroelectric and ferromagnetic proprieties. Thus, for understanding the mechanism inherent to the macroscopic proprieties local probe studies, for acquiring information about the electronic structure, are of the most importance. Therefore, a Perturbed Angular Correlation (PAC) study was carried out in the AgCrO2 system. For that purpose high purity samples were synthesized by solid-state reaction. Macroscopic characterization via structural, morphological, magnetic and electric analysis has been performed.
The PAC studies have been performed from 800 K to 11K, with special focuses in the vicinity of the magnetic phase transition temperature. The results show the coexistence of two distinct local environments. The nature of these two Ag surroundings will be discussed.
References:
1. Y.H. Chu, L.W. Martin, et al, Nature Materials 7, 478 (2008).
2. M. Bibes and A. Barthélémy, Nature Materials 7, 425 (2008).
3. S. Seki et al, Phys. Rev. Lett. 101, 067204-1, (2008)
Authors
Armandina Lima Lopes
(Centro de Física Nuclear, Universidade de Lisboa)
Gonçalo Oliveira
(Centro de Física Nuclear, Universidade de Lisboa)
João Guilherme Correia
(Instituto Tecnológico e Nuclear, Sacavém)
João Pedro Araújo
(Instituto de Nanociência e Nanotecnologia, Universidade do Porto)
Tânia Mendonça
(Instituto de Nanociência e Nanotecnologia, Universidade do Porto)
Vítor Amaral
(Departamento de Física e CICECO, Universidade de Aveiro)
