Doping through the percolation limit in GeNi2−xCoxO4

The solid solutions GeNi2−xCoxO4 have been prepared to examine the difference in ground states between integer and non-integer spins on the corner-shared tetrahedra lattice. It is found that there is a change in the evolution of the Weiss constant, and the magnetic transition temperatures near the percolation limit for the pyrochlore lattice. Substitution with Ni2+ results in a filling of the t2g orbitals and acts like a non-magnetic impurity. …