At what temperature does ammonium sulphate become ferroelectric?
-
A.
0°C
-
B.
100°C
-
C.
25°C
-
D.
−49.5°C
Correct Answer:
D. −49.5°C
Explanation:
Ammonium sulfate undergoes a phase transition to a ferroelectric state at temperatures below -49.5°C. At this critical temperature, known as the Curie temperature, the material's crystal lattice shifts from an orthorhombic paraelectric structure to the orthorhombic polar space group Pna21. This structural change results in spontaneous polarization, a defining characteristic of ferroelectric materials. Consequently, while the substance remains paraelectric at room temperature, it exhibits ferroelectric behavior only when cooled below this specific threshold.
Click below to open Discussion & Feedback
0 Issues
Please
login to comment or Report Issues.