Magnetism of single-doped paramagnetic tin clusters studied using temperature-dependent Stern-Gerlach experiments with enhanced sensitivity: impact of the diamagnetic ligand field and paramagnetic dopant.

In this work, the magnetic properties of tetrel clusters Sn N TM, which are singly doped with transition metals (TM), are investigated. On the one hand, the number of tetrel atoms ( N = 11, 12, 14 and 17 with TM = Mn) is varied; on the other hand, different transition metals ( N = 14, TM = Cr, Mn, Fe) are studied. Magnetic deflection experiments under cryogenic conditions show that the variation of the number of tetrel atoms strongly changes the magnetic properties of the Mn-doped clusters. It is observed that Sn 12 Mn, Sn 11 Mn and Sn 14 Mn partially show super-atomic behaviour, while spin relaxation occurs in Sn 17 Mn. Magnetic deflection experiments at higher nozzle temperatures were carried out for the first time enhanced by a second parallel-aligned Stern-Gerlach magnet to achieve larger deflections. The resulting temperature-dependent one-sided deflections are quantitatively analysed using Curie's law and show that Sn 17 Mn possesses the highest magnetic moment of these clusters, followed by Sn 12 Mn and Sn 11 Mn. Sn 14 Mn shows the lowest magnetic moment. The replacement of Mn by Cr in Sn 14 Mn leads to a diamagnetic singlet, i.e. , the magnetic moment of Cr in Sn 14 Cr is completely quenched. The replacement of Mn by Fe in turn leads to a paramagnetic species, whereby Sn 14 Fe is most likely present as a triplet. On this basis, the geometrical and electronic structures are analysed using quantum chemical calculations, indicating an arachno-type structure for Sn 14 Cr, Sn 14 Mn and Sn 14 Fe, which has already been predicted in the literature for Si 14 Cr. This is experimentally confirmed by deflection of molecular beams with an electric field under cryogenic conditions, suggesting that the arachno-type geometry is crucial for the overall stability of the transition-metal-doped tetrel clusters Sn 14 TM with TM = Cr, Mn, Fe.