Specific Heat and Magnetic Interactions in Spin Ladder Gadolinium and Copper-Based Molecular Ferromagnets

The compounds Gd2(ox)[Cu(pba)]3[Cu(H2O)5] · 20H2O (1) and Gd2[Cu(opba)]3 · 6DMSO · 4H2O (2) are spin ladder-based molecular ferromagnets. Low-temperature specific heat measurements show that both compounds undergo three-dimensional magnetic ordering with Tc = 1.05 K for (1) and Tc = 1.78 K for (2). These materials represent the unique examples of long-range ordering, reported so far, for gadolinium and copper-based molecular magnets.