A spinel is an important class of oxides consisting of two types of metal ions with the oxide ions arranged in ccp layers. The normal spinel has $$one-eighth$$ of the tetrahedral holes occupied by one type of metal ion and $$one-half$$ of the octahedral holes occupied by another type of metal ion. Such a spinel is formed by $$Mg2+$$,$$Al3+$$ and $$O2$$−. The neutrality of the crystal is being maintained. Antispinels will differ in arrangements among cations, but anions will be still fcc . The formula of the spinel is: Type of hole occupied by $$Al3+$$ ions in inverse spinel will be Type of hole occupied by $$Mg2+$$ ions is:

Question

A spinel is an important class of oxides consisting of two types of metal ions with the oxide ions arranged in ccp layers. The normal spinel has $$one-eighth$$ of the tetrahedral holes occupied by one type of metal ion and $$one-half$$ of the octahedral holes occupied by another type of metal ion. Such a spinel is formed by $$Mg2+$$,$$Al3+$$ and $$O2$$−. The neutrality of the crystal is being maintained. Antispinels will differ in arrangements among cations, but anions will be still fcc . The formula of the spinel is:   Type of hole occupied by $$Al3+$$ ions in inverse spinel will be Type of hole occupied by $$Mg2+$$ ions is:

Infinity Learn · Accepted Answer

$$Mg+2$$ is in tetrahedral hole, and two $$Al+3$$ ions in half of octahedral holes constituting a total charge of $$+8in$$ inverse spinel $$M+3$$ occupy one in tetrahedral hole and one in octahedral holealways occupy tetrahedral hole either in spinel or antispinel .

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