Phase diagrams of antiferroelectric and ferroelectric perovskites
The dielectric properties of these materials are studied in close collaboration with Francesco Cordero for the anelastic properties. Recent results allowed to refine the phase diagram of La-doped PbZr0.9Ti0.1O3, interesting for electro-optical applications, high energy density capacitors, digital displacement transducers etc., near the phase boundary between competing antiferroelectric and ferroelectric phases.
F. Craciun et al., J. Appl. Phys. 117, 184103 (2015).
Multiferroicity of ferroelectric perovskites doped with magnetic impurities
Multiferroic materials that exhibit simultaneously magnetic and ferroelectric (FE) order are investigated due to their potential applications in multifunctional sensors, spintronics, data storage, etc. We found emergent magnetic properties in (Sm,Fe)-doped PbTiO3 FE perovskite and an abnormal behavior of dielectric constant and loss below the temperature where the magnetization also increases. HRTEM evidenced a polar nanostructure, besides normal FE domains.
F. Craciun et al., Appl. Phys. Lett. 102, 242903 (2013).
F. Craciun et al., J. Appl. Phys. 116, 074101 (2014).
Nano/macro domain transitions in nanostructured polar materials
We have investigated thermally driven and electrically driven nano/macro domain transformations in different nanostructured polar materials like NBT-BT and PLZT.
Such transformation has been evidenced also in epitaxial PLZT thin films under anisotropic strain.
F. Craciun et al., Appl. Phys. Lett. 102, 162902 (2013).
F. Craciun et al., J. Appl. Phys. 112, 124106 (2012); N. Scarisoreanu et al., J. Appl. Phys. 116, 074106 (2014);
F. Craciun, Phys. Rev. B 81, 184111 (2010).