Crystal Chemistry and Polymorphism of Potassium–Magnesium Monophosphate

✍ Scribed by G. Wallez; C. Colbeau-Justin; T. Le Mercier; M. Quarton; F. Robert

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 404 KB
• Volume: 136
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7671

✦ Synopsis

The new compound KMgPO 4 has been synthesized, and its structure has been determined at room-temperature ( form): space group is P2 1 /c (No. 14) with cell parameters a ‫؍‬ 8.549(2) A s , b ‫؍‬ 5.078(1) A s , c ‫؍‬ 18.996(2) A s , ‫؍‬ 91.68(1)°°, and Z ‫؍‬ 8. Phase transitions occur at 362 and 422°°C, -KMgPO 4 and -KMgPO 4 are orthorhombic, respectively Pna2 1 (No. 33) and Pnma (No. 62). The and forms are related to the tridymite type, with a skeleton made of MgO 4 and PO 4 tetrahedra, but in form, half of the magnesium atoms are pentacoordinated.