Interplay of magnetic field and interlayer coupling in the quasi-two-dimensional quantum magnet Cu(en)Cl2 : Realization of the spin-1/2 rectangular/zigzag square Heisenberg lattice

Phase Transformation in Quasi-Two-Dimensional Quantum Antiferromagnet Cu(tn)Cl2 (tn = 1,3-Diaminopropane)

“…Although the magnetic contribution dominates at low temperatures, its behavior in Cu­(tn)­Cl 2 is quite different from that encountered in similar compound Cu­(en)­Cl 2 (en=ethylenediamine = C 2 H 8 N 2 ). There is a sharp λ-like anomaly in the specific heat of Cu­(en)­Cl 2 below 1 K, which is typical for the magnetic phase transition and the onset of long-range order . Such a behavior is, however, not observed in the low-temperature specific heat of Cu­(tn)­Cl 2 , which exhibits a broad hump in the vicinity of 2 K. These differences are likely to result from much stronger interlayer magnetic interactions in Cu­(en)­Cl 2 in comparison to those in Cu­(tn)­Cl 2 and they remain correlated with differences in the low-temperature crystal structures of these compounds.…”