Abstract
The transport and dielectric properties of ${\mathrm{Sr}}_{0.97}({\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}){\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ solid solutions have been investigated at temperatures $1.5\mathrm{K}<~T<~300\mathrm{K}$ and frequencies $20\mathrm{Hz}<~\ensuremath{\nu}<~1\mathrm{MHz}.$ Depending on x, suppression of the quantum-paraelectric background, dielectric anomalies associated with relaxational processes, variable-range-hopping conduction, and a sublinear power-law increase in the ac conductivity were observed. The results of the present work are the following: (i) For low concentration Fe doping, the suppression of the paraelectric state is smaller than for Bi and La doping; the higher stability of the quantum paraelectric state is due to the fact that, in contrast to Bi and La, Fe substitutes for Ti sites. (ii) The observed variable-range-hopping (VRH) conduction indicates that Fe doping leads to the occurrence of local states in the highly disordered ${\mathrm{SrTiO}}_{3}$ lattice; this behavior coexists with the stable quantum paraelectric state. (iii) A dielectric relaxation process from 50 to 200 K is observed that is related to some defects; it is evidenced that the dielectric relaxation has no direct relation with the VRH mechanism, however, it is very possibly related to a polaron mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
