A study on thermoelectric performance and magnetic properties of Ti-doped Bi2Sr2Co1.8Oy ceramic materials


Ozcelik B. , Cetin G., Gursul M., Madre M., Sotelo A.

MATERIALS CHEMISTRY AND PHYSICS, cilt.256, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 256
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.matchemphys.2020.123701
  • Dergi Adı: MATERIALS CHEMISTRY AND PHYSICS

Özet

Within this study, Bi2Sr2Co1.8-xTixOy ceramic materials (x = 0, 0.05, 0.10, and 0.15) in different forms (bulk, asgrown and annealed fibers) have been produced through the solid state method and textured using the laser floating zone technique. XRD yields similar patterns for all sintered samples and annealed fibers, with major peaks corresponding to the Bi2Sr2Co1.8Oy thermoelectric phase. When observing the different contrasts appearing in the SEM-EDS analysis, it can be deduced that as-grown samples are multiphasic due to their incongruent melting. On the other hand, laser floating zone technique provides good grain alignment, reducing electrical resistivity values. The Seebeck coefficient of all samples is positive demonstrating a conduction mechanism mainly governed by holes. From magnetization and magnetic hysteresis measurements, it can be observed that magnetization values increase with decreasing temperature (dM/dT < 0) and the dM/dH ratio slightly decreases with increasing Ti content.