orthorhoferroelectrics

Orthorhoferroelectrics are a class of ferroelectric materials that exhibit their spontaneous electric polarization along one of the crystallographic axes within an orthorhombic unit cell. Ferroelectricity is a property of certain dielectric materials that possess a spontaneous electric dipole moment, which can be reversed by an external electric field. In orthorhombic ferroelectrics, this polarization is not aligned along the highest symmetry axes (like in tetragonal or rhombohedral ferroelectrics) but rather along one of the three equivalent axes of the orthorhombic structure. This results in a lower symmetry crystal structure when the material is in its ferroelectric state.

The transition to the ferroelectric state from a higher-symmetry paraelectric phase (often cubic or tetragonal) in orthorhoferroelectrics involves a structural distortion that lowers the crystal symmetry to orthorhombic. The spontaneous polarization in these materials can be switched between different crystallographic directions within the orthorhombic system, similar to how polarization can be switched in other ferroelectric classes. The specific crystallographic orientation of the polarization is a key characteristic of orthorhoferroelectric behavior.

Examples of materials that can exhibit orthorhoferroelectric phases include certain perovskite oxides like bismuth ferrite (BiFeO3) under specific conditions or compositions. The study of orthorhoferroelectrics is important for understanding the complex phase transitions in ferroelectric materials and for developing new devices that leverage their unique polarization switching characteristics. Their behavior can be influenced by factors such as temperature, pressure, and strain.