Magnetization and dynamics of reentrant ferrimagnetic spin-glass [MnTPP]::+[TCNE].−⋅2PhMe

We present direct current (dc) magnetization M(T,H) and alternating current (ac) susceptibility χac(T,H,f) data for the quasi-one-dimensional molecule-based ferrimagnet [MnTPP]::+[TCNE].−⋅2PhMe (TPP=meso-tetraphenylporphyrinato, TCNE=tetracyanoethylene). Static scaling of the real part χ′ of the ac susceptibility and data collapse of M(T,H) over a limited reduced temperature range above Tc≊13 K lead to the critical exponents γ≊1.6, β≊0.5, and δ≊4.2. Below Tc, χac depends sensitively on frequency and exhibits a striking double-peak structure similar to that found in reentrant spin glasses. Possible models for the frequency dependence of the peaks observed in χac are discussed.