Structures of lonic solids based on hcp Rutile(Tio2) Structure Rutile structure CHCP anion lattice Octahedral holes occupi Ti for octahedral coordination s6.3)Coordination ETiO,-octahedra SOTi3-trigonalplanar 802 ions are in HCP aTiOs are in cornersharing along a and b directions; in edge sharing along c direction Rutile: ceramic pigment(white color) aUnit cell dimensions: a=4.5937A; c=2.9587 A Rutile Crystal Structure Anatase TiO2 )Structure 0=0+000°9 %,(%u)(%+u)%,u=0.31 锯O2 ions are in CCp sTiO are all in edge ompounds with the same structures: GeO., SnO,, PbO 00③ cRystal system MnO2、MoO2、NbO2wO2 A Structures of lonic solid Spinel Structure Some other ionic solid structures named for the mineral MgAlyo- general formula AB,Oa FCC array of- ions A cations occupy 1/8 of T holes pecies occupying holes O. Characteristic of some d-block oxides Fe,Ok Co O Mn Oa10 Structures of Ionic Solids Based on HCP Rutile Structure HCP anion lattice ¾ ½ Octahedral holes occupied Arises from the preference of Ti for octahedral coordination (6,3) Coordination TiO6 –octahedra OTi3 –trigonalplanar Rutile: ceramic pigment (white color) Rutile (TiO2 ) Structure O2- ions are in HCP. TiO6 are in corner-sharing along a and b directions; in edge-sharing along c direction Crystal system:tetragonal Unit cell dimensions: a=4.5937 Å; c=2.9587 Å Rutile Crystal Structure Ti4+：000，½ ½ ½ O2- : uu0, (1-u)(1-u)0, (½+u)(½-u) ½, (½-u)(½+u) ½, u=0.31 Compounds with the same structures: GeO2、SnO2、PbO2、 MnO2、MoO2、NbO2、WO2、 CoO2、MnF2 and MgF2 etc． Anatase (TiO2 ) Structure O2- ions are in CCP. TiO6 are all in edge￾sharing . Crystal system: tetragonal Unit cell dimensions a = 3.7845 Å c = 9.5143 Å Structures of Ionic Solids Some other ionic solid structures Spinel –¾ named for the mineral MgAl2O4 –¾ general formula AB2O4 FCC array of O2- ions •A cations occupy 1/8 of T holes •B cations occupy ½ of O holes •Sometimes denoted A[B2 ]O4 •Square brackets indicate species occupying O holes •Characteristic of some d-block oxides •Fe3O4 , Co3O4 , Mn3O4 Spinel Structure