“…A quantitative measure of the frequency shift of v 00 m is obtained from / = DT p /[T p D(log f)] = 0.04, which is comparable to a spin-glass rather than a superparamagnet (/ > 0.1) [23,24]. It should be noted that weak ferromagnetic ordering has been found in several metal phosphonates [4,5,19,25]. However, compound 1 shows the coexistence of spin-glass-like behavior, which is quite rare in metal phosphonate chemistry.…”