Related Experiment Video
Updated: May 13, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Composition- and temperature-driven structural transitions in Bi(1-x)Ca(x)FeO3 multiferroics: a neutron diffraction
V A Khomchenko1, I O Troyanchuk, D M Többens
1CEMDRX/Department of Physics, University of Coimbra, Coimbra, Portugal.
Abstract:
Neutron powder diffraction and magnetization measurements of the Bi(1-x)Ca(x)FeO3 (0.05 ≤ x ≤ 0.14) compounds were carried out to follow the effect of the heterovalent A-site doping on the long-range structure and magnetic properties of the BiFeO3 multiferroic. Ca substitution induces the appearance of weak ferromagnetism in the initial ferroelectric R3c phase, but modifies the picture of polar displacements, so the average PbZrO3-like antiferroelectric structure is stabilized at x = 0.11. Further increase of the Ca content leads to transformation of the antipolar ionic shifts to give rise to the Pbam → Imma transition near x = 0.14. A structural study performed for the x = 0.05 compound at high temperature revealed the R3c → Pnma phase transition at 950 K. For x = 0.1 samples, an intermediate heating-induced structure separating the R3c and Pnma phases was found.
Related Concept Videos
Ferromagnetism
Imperfections in Crystal Structure: Non-Stoichiometric Defects
Phase Transitions: Melting and Freezing
Ionic Crystal Structures
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...
Molecular and Ionic Solids
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...
Imperfections in Crystal Structure: Stoichiometric Point Defects

