  The isovector M1 transitions between low-lying T=1 and T=0 states in odd-odd
N=Z nuclei are analyzed. Simple analytical expressions for M1 transition
strengths are derived within a single-j-shell approximation for both j=l+1/2
and j=l-1/2 cases. The large B(M1) values for the j=l+1/2 case are attributed
to quasi-deuteron configurations. The B(M1) values for the j=l-1/2 case are
found to be small due to partly cancellation of spin and orbital parts of the
M1 matrix element.
