Spin only magnetic moment is 3.6 ×10-23 A.m2 for
Ti2+
Zn2+
Co2+
Cu2+
Spin only magnetic moment, μs=nn+2 B.M ; n=number of unpaired electrons ;
One B.M (Bohr Magneton) = 9.273×10-24 A.m2 ;
Sc3+, Ti4+, Cu+, Zn2+…..n=0, μs=0 ; Diamagnetic
Ti3+, Cu2+…..n=1, μs=3=1.732 B.M=1.732×9.273×10-24 A.m2 ;
Ti2+, V3+, Ni2+…..n=2, μs=8=2.82 B.M=2.82×9.273×10-24 A.m2 ;
Cr3+, V2+,Co2+…..n=3, μs=15=3.87 B.M=3.87×9.273×10-24 A.m2 ;
Co3+, Fe2+, Mn3+, Cr2+…..n=4, μs=24=4.9 B.M=4.9×9.273×10-24 A.m2 ;
Fe3+, Mn2+…..n=5, μs=35=5.9 B.M=5.9×9.273×10-24 A.m2 ;
μobs>μcal ......Fe2+, Co2+, Ni2+ ; In these cases orbital contributon cannot be ignored.