Structural, morphological, Raman, dielectric and electrical properties of La1-2 Ba Bi FeO3 (0.00 ≤ x ≤ 0.20)
E M Benali1,2, A Benali1,2,3, M Bejar1
1Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax B.P. 1171 3000 Sfax Tunisie benaliemna93@gmail.com.
RSC Advances
|May 2, 2022
Summary
Lanthanum Barium Bismuth Iron Oxide nanoparticles were synthesized and characterized. Their electrical properties reveal a consistent conduction mechanism, with charge carrier binding energy increasing upon substitution.
Area of Science:
- Materials Science
- Solid State Chemistry
- Nanotechnology
Background:
- Perovskite oxides exhibit diverse electrical properties.
- Lanthanum Barium Bismuth Iron Oxide (La$_{1-x}$Ba$_x$BiFeO$_3$) is a promising material for electronic applications.
- Understanding the synthesis-structure-property relationships is crucial for material optimization.
Purpose of the Study:
- To synthesize La$_{1-x}$Ba$_x$BiFeO$_3$ nanoparticles using an auto-combustion method.
- To characterize the structural and electrical properties of the synthesized nanoparticles.
- To investigate the conduction mechanism and its dependence on Ba substitution.
Main Methods:
- Auto-combustion synthesis using glycine as fuel.
- X-ray diffractometry (XRD) for structural analysis.
- Williamson-Hall formalism for crystallite size calculation.
- Impedance spectroscopy (frequency dependence of Z'' and M'') to study relaxation processes.
- Nyquist plots for equivalent circuit analysis.
- Analysis of Jonscher's power law for conduction mechanism.
Main Results:
- Orthorhombic structure (Pnma space group) confirmed for synthesized La$_{1-x}$Ba$_x$BiFeO$_3$ nanoparticles.
- Minor secondary phase observed for x > 0.1.
- Relaxation processes follow Arrhenius law.
- Equivalent circuit analysis reveals grain and grain boundary contributions.
- Similar activation energies calculated from impedance and modulus data.
- Non-Symmetric Power Law (NSPT) conduction mechanism identified.
- Binding energy of charge carriers (W_H) increases with Ba substitution.
Conclusions:
- The auto-combustion method is effective for synthesizing La$_{1-x}$Ba$_x$BiFeO$_3$ nanoparticles with controlled structure.
- Electrical properties are dominated by grain and grain boundary effects.
- The NSPT conduction mechanism is consistent across all compositions.
- Ba substitution enhances the binding energy of charge carriers, influencing electrical conductivity.
Related Concept Videos
03:02Colors and Magnetism
12.4K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.4K
02:42Ionic Crystal Structures
15.3K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
15.3K
02:54Trends in Lattice Energy: Ion Size and Charge
24.4K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
24.4K
02:54Molecular and Ionic Solids
18.1K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
18.1K
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K