Chemistry and Physics of Molecular-Based Inorganic Compounds Exhibiting a Spontaneous Magnetization

One of the main challenges in the field of the molecular materials is the design of molecular-based ferromagnets. Our basic strategy along this line consists of assembling ferrimagnetic chains within the crystal lattice in a ferromagnetic fashion. This can be achieved owing to the (almost) limitless flexibility of the molecular chemistry. The chains may be either regular or alternating. Examples of both situations are presented. MnCu(pbaOH)(H₂O)₃ with pbaOH=2-hydroxy-1,3-propylenebis(oxamato) is a regular chain compound ordering ferromagnetically at T_C=4.6 K, and MnCu(obbz).1H₂O with obbz=oxamido-N,N′-bis(2-benzoato) is an alternating chain compound exhibiting a spontaneous magnetization below T_C=14 K. To get information on the mechanism of the magnetic ordering, a broad spectrum of physical techniques is utilized, including magnetic susceptibility and magnetization measurements, EPR spectroscopy and heat capacity data. The perspectives in this new field are outlined.