Comparative investigation of the spin-crossover compounds Fe(btz)2(NCS)2 and Fe(phen)2(NCS)2 (where btz = 2,2'-bi-4,5-dihydrothiazine and phen = 1,10-phenanthroline). Magnetic properties and thermal dilatation behavior and crystal structure of Fe(btz)2(NCS)2 at 293 and 130 K | Publicación