Field-induced ferromagnetism due to magneto-striction in 1-D helical chains
Bikash Kumar Shaw, Mithun Das, Anik Bhattacharyya, Biswa Nath Ghosh, Susmita Roy, Prabhat Mandal, Kari Rissanen, Shouvik Chattopadhyay, Shyamal Kumar Saha
Two homochiral copper(II) helices, [Cu(μ1,3-N3)(L1)]n (1) and [Cu(μ1,3-NCO)(L2)]n (2), with end-to-end pseudohalide bridges, were synthesized using two N2O donor achiral Schiff bases viaspontaneous chiral resolution. Field-induced ferromagnetic ordering due to magneto-striction in homochiral 1-D helix [Cu(μ1,3-N3)(L1)]n (1) is reported for the first time. At temperatures below 5.5 K, under a magnetic field of 1 T, orthogonality between the magnetic orbitals of copper centres increases significantly due to the contraction of lattice parameters, giving rise to long-range ferromagnetic ordering in the helical chain. The magneto-dielectric results are also indicative of the observed magneto-striction effect in the present complex 1. We believe that this study will uncover a new way to invoke long-range ferromagnetic ordering in 1-D helical chains.
Circular dichroism, Materials, Inorganic chemistry