Intrinsic organic-based synthetic/artificial antiferromagnets.

Mn(TCNE)[C4(CN)8]1/2 (TCNE = tetracyanoethylene) and [NEt4]Mn(II)3(CN)7 have extended layers with nearest neighbor intralayer S = 5/2 and S = 1/2 spin sites that couple antiferromagnetically forming ferrimagnetic layers. These layers are uniformly connected via diamagnetic (nonmagnetic) bridging μ4-(C4(CN)8 (8.77 Å) or μ-CN (5.48 Å) ligands, respectively, that antiferromagnetic couple the ferrimagnetic layers resulting in an antiferromagnet. The Jinter/kB is -1.0 and -1.8 K (H=-JSi⋅Sj) for Mn(TCNE)[C4(CN)8]1/2 and [NEt4]Mn(II)3(CN)7, respectively. Albeit intrinsically multilayered, these antiferromagnets have the same motif as that for artificial/synthetic antiferromagnets that exhibit giant magnetoresistance (GMR) and are commercially used in many magnetic memory applications.