Field Supported Slow Magnetic Relaxation in a Mononuclear Cu(II) Complex

Abstract

A mononuclear hexacoordinate Cu(II) complex shows a field induced slow magnetic relaxation that is not facilitated by an energy barrier to spin reversal due to the zero-field splitting. Two relaxation channels were found: the magnetic field strongly supports the low-frequency relaxation path with a relaxation time as long as τ = 0.8 s at T = 1.9 K and B = 1.5 T. The mechanism of the relaxation at low temperature involves the dominant Raman process for this S = 1/2 spin system along with a temperature-independent term belonging to a quantum tunneling.

Magnetization Slow Dynamics in Ferrocenium Complexes

“…Remarkably, this simple approach reproduces extremely well the experimental data with an exponent ( n ) of 3.8(1) for the Raman term, suggesting that relaxation involves both optical and acoustic phonons . It is worth mentioning that, while Kramers ions are expected to have n= 9, smaller n values have been observed in a number of S = transition metal complexes which display slow relaxation of the magnetization …”

Single Ion Magnets from 3d to 5f: Developments and Strategies

“…[Cu II (pydca)(dmpy)] ⋅ 0.5 H 2 O ( 47 ), the analogue of 42 , shows slow relaxation behaviour, which is dominated by the Raman process.…”

Microwave assisted synthesis of heterometallic 3d–4f M4Ln complexes

“…The low temperature peak is related to the application of a dc field and is important at low temperatures and low frequencies, as discussed for Ni(II), Co(II) and Cu(II) SMMs by Titis and Boca. 58,59 The ac susceptibility for Co 4 Dy was also studied as a function of frequency at several temperatures, (ESI Figure S04-05). The data were fitted to a Debye model for a distribution of relaxation processes with τ o = 8e-5-9.4e0-3 s -1 and α = 0.04-0.31 between 5 and 13 K. The values for each temperature can be found in the ESI Table S01.…”