PHYSICS · Subjective · Fermi University Physics · Condensed Matter, Materials & Soft Matter · Crystal structure, bonding and diffraction · Crystal structure, bonding and diffraction
Condensed Matter Physics, Ch What holds a solid together, and where its atoms sit
Problem
Strontium titanate, SrTiO3, has the cubic perovskite structure, with cube edge a=3.905A˚: a strontium ion at every corner of the cube, a titanium ion at the body centre, and an oxygen ion at the centre of every face. Give the Bravais lattice and write out the basis, then use the sharing rule to show that one conventional cube holds exactly one formula unit of SrTiO3. Finally, find the distance from the titanium ion to its nearest oxygen ions and from a strontium ion to its nearest oxygen ions, and how many oxygen ions surround each at that distance.