Influence of transition element Os substitution on the structural and electrical features of perovskite structure LaCr1−xOsxO3. (April 2020)

• Record Type: Journal Article
• Authors: Polat, O.; Coskun, M.; Coskun, F.M.; Zlamal, J.; Durmus, Z.; Caglar, M.; Turut, A.
• Is Part Of: Materials research bulletin. Volume 124(2020)
• Publication Date: 2020-04
• Subjects: LaCrO3 -- Os doping -- Solid-state method -- Electrical modulus -- Dielectric constant -- Conductivity; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2019.110759
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Fig. Comparison of real part of the dielectric constant for LaCrO3, LaCr0.99 Os0.01 O3, LaCr0.97 Os0.03 O3, and LaCr0.95 Os0.05 O3 at a) -100 °C, b) 20 °C and c) 100 °C. Highlights: The electrical properties of LaCrO3 were modified by doping of Os transition into Cr atom. Os-doped LCO materials were synthesized by solid-state reaction technique. A wide range of investigation on doping evaluation of Os into Cr cation in LCO perovskite structure has been performed at -100 °C to +100 °C temperature range. The conductivity and the dielectric values of the LCO improve with Os dopant. Various conduction model needs to be considered to explain the conduction in the undoped and Os doped LCO compounds. Abstract: This study aims to investigate the electrical properties of LCO compound under Os doping into Cr sites with different substitution levels. The crystalline structure of LaCrO3 and LaCr1-x Osx O3 (LCOO) (x = 0.01, 0.03, 0.05) was inspected with X-ray diffractometer (XRD). Scanning electron microscope (SEM) was utilized to observe the particle/powder morphology. Moreover, the valence states of the elements were investigated by X-ray photoelectron spectroscopy (XPS). The electrical modulus, dielectric constant and conductivity of the LCO and LCOO pellets were detailed by dielectric/impedance spectroscopy studies at different frequencies and temperatures. The temperature dependent power law exponent, calculated through conductivity versus temperature measurements, exhibited that different conduction models are needed to consider for the conductivity mechanism. Furthermore, it has been realized that the activation energies determined from electrical modulus and dc conductivity are close to each other.