title: Dielectric and Mössbauer studies of ferroelectric and magnetic phase transitions in A-site and B-site substituted multiferroic PbFe0.5Nb0.5O3.
abstract: In the present study, we diluted either A- or B- sublattice of perovskite multiferroic PbFe(0.5)Nb(0.5)O(3) (PFN) and studied the changes of the magnetic and ferroelectric phase transition temperatures and dielectric properties caused by such dilution. Dielectric studies of PFN single crystals show that, in contrast to the commonly adopted view, the ferroelectric phase transition in PFN is non-diffused and the relaxor-like behavior usually observed in ceramic samples has an extrinsic nature. A-site substitutions (Ba, Ca) lead to the smearing of the permittivity-temperature maximum, lowering its maximum temperature, T(m) and inducing relaxor behavior. B-site diluting of PFN by Ti increases T(m) and only slightly affects the permittivity maximum diffuseness. Both A-site and B-site substitutions in PFN lead to lowering of its Neel temperature, T(N). However, above a certain compositional threshold, fast lowering of T(N) stops and a new magnetic state with comparatively high (~50K) transition temperature becomes stable in a rather wide compositional range.
authors.affiliation: Research Institute of Physics and the Facultyof Physics, Southern Federal University, Rostov on Don, Russia. igorraevsky@gmail.com
authors.forename: Igor P
authors.initials: IP
authors.lastname: Raevski
authors.forename: Stanislav P
authors.initials: SP
authors.lastname: Kubrin
authors.forename: Svetlana I
authors.initials: SI
authors.lastname: Raevskaya
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Prosandeev
authors.forename: Maria A
authors.initials: MA
authors.lastname: Malitskaya
authors.forename: Victor V
authors.initials: VV
authors.lastname: Titov
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Sarychev
authors.forename: Aleksei V
authors.initials: AV
authors.lastname: Blazhevich
authors.forename: Irina N
authors.initials: IN
authors.lastname: Zakharchenko