Morphotropic transition

{
  "id": "MLC-T-CHM-007584",
  "term": "Morphotropic transition",
  "field": "Chemistry",
  "definition": "An abrupt change of crystal structure in a solid solution as its composition is varied across the series, such as the boundary between rhombohedral and tetragonal phases in lead zirconate titanate. The two sides have different symmetry, and the boundary runs nearly vertically on a temperature-composition diagram. Piezoelectric coefficients in lead zirconate titanate peak close to it, near a Zr to Ti ratio of 52 to 48.",
  "subject": "Inorganic Chemistry",
  "see_also": [
    "mixed crystal"
  ],
  "references": [
    "PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 587 (https://doi.org/10.1351/pac199466030577)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/morphotropic-transition/"
}