Title :
High-frequency dielectric study of multiferroic Bi0.9La0.1Fe0.9Mn{0.1}O3 thin films
Author :
Sobiestianskas, R. ; Vengalis, B. ; Banys, J.
Author_Institution :
Fac. of Phys., Vilnius Univ., Vilnius, Lithuania
Abstract :
La- and Mn-doped multiferroic BiFeO3 thin films were fabricated and characterized at radio- and microwave frequencies using the parallel-plate capacitor structures at a room temperature. A single phase epitaxial-quality thin films were grown by RF sputtering on SrTiO3(100) substrate with highly conductive SrRuO3 and Ti/Au layers used as bottom and top electrodes. In the frequency range 40 MHz - 30 GHz the Bi0.9La0.1Fe0.9Mn0.1O3 (BLFMO) films show relatively low losses and dielectric constant value close to 90. Analysis of the frequency dependences of loss tangent shows power law 1/3 with estimated value of microwave loss tangent less than 0.06 at frequencies below 20 GHz. We assume that the oxygen vacancies in the thin film act as charged defects and cause extrinsic microwave losses.
Keywords :
bismuth compounds; dielectric losses; epitaxial layers; ferroelectric thin films; lanthanum compounds; multiferroics; permittivity; sputtered coatings; vacancies (crystal); Bi0.9La0.1Fe0.9Mn0.1O3; RF sputtering; SrRuO3-SrTiO3; SrTiO3; Ti-Au; bottom electrodes; charged defects; dielectric constant; dielectric losses; frequency 40 MHz to 30 GHz; microwave frequencies; microwave loss tangent; multiferroic thin films; oxygen vacancies; parallel-plate capacitor structures; power law; radiowave frequencies; single phase epitaxial-quality thin films; temperature 293 K to 298 K; top electrodes; Bismuth; Capacitors; Conductive films; Dielectric thin films; Frequency estimation; Microwave frequencies; Radio frequency; Sputtering; Substrates; Temperature;
Conference_Titel :
Applications of Ferroelectrics, 2009. ISAF 2009. 18th IEEE International Symposium on the
Conference_Location :
Xian
Print_ISBN :
978-1-4244-4970-5
Electronic_ISBN :
1099-4734
DOI :
10.1109/ISAF.2009.5307574
