Structural, dielectric, and Mossbauer studies of multiferroic (1-x)PbFe_0.5Nb_0.5O₃ - xPbCr_0.5Nb_0.5O₃ solid solution ceramics obtained by usual sintering and by high-pressure synthesis

ABSTRACT

In the(1-x)PbFe_0.5Nb_0.5O₃ - xPbCr_0.5Nb_0.5O₃ (PFN-xPCN) ceramics fabricated by a usual solid state synthesis route the content of the pyrochlore phase increases dramatically with x, exceeding 50% for x = 0.3 composition. Synthesis under high (6 GPa) pressure enabled us to obtain perovskite PFN-xPCN ceramics, though for compositions with x ≥ 0.4 an admixture of the pyrochlore phase was still present. Both the pseudocubic lattice parameter and ferroelectric phase transition temperature decrease monotonically as x grows. The composition dependence of the antiferromagnetic phase transition temperature for PFN-xPCN is very similar to that in the PFN-PbMO₃ (M-Ti, Zr, Sn) solid solution systems implying the lack of magnetic exchange between Fe³⁺ and Cr³⁺ ions.

KEYWORDS:

• PbFe_0.5Nb_0.5O₃
• PFN
• PbCr_0.5Nb_0.5O₃
• high-pressure synthesis
• Mossbauer spectra

Funding

This work was partially supported by the Ministry of Education and Science of the Russian Federation (project 3.1649.2017/PP) and the University of Macau under Research & Development Grant for Chair Professor No RDG007/FST-CHD/2012.

S.I.R., S.P.K, and V.V.T. are grateful for the Russian Foundation for Basic Research for the support under grant 16-52-00072 Bel_a. A.V.P., N.M.O., and Y.V.R. acknowledge the support by the Belarusian Republican Foundation for Fundamental Researches under grant T16R-079.