2. In the fluorite structure shown here, the large atoms are Fand the small atom

Question

2. In the fluorite structure shown here, the large atoms are Fand the small atoms are Ca2. (20 pts total) Fluorite CaF2 The crystal structure can be described as Fm3m in Hermann-Mauguin notion. What does the "F" in the space group mean? (5) a. b. The Strukturbericht for this structure is C1. If there are 12 atoms per unit cell, what would the Pearson be for this structure? (5) In this structure the Ca2+ ions have CN-8 and sit on face-centered cubic sites. The F atoms site in the tetrahedral sites between the Ca2+ ions. What is the fluorine ion coordination number? (5) c. d. There is a Schottky defect in this CaF2. Write it in Kröger-Vink notation. (5)

Explanation / Answer

(a) F means face center cubic

(c) The Fluorine ion coordination number is 4

(d) VCa "  a calcium vacancy with double negative charge

VF· a flourine vacancy with single positive charge

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.