Surface Investigation on Gd4M8(M = Zn, Ni) Single Molecule Coolers

Proving the preservation of functionality at the molecular scale is still a major challenge, both for the choice of suitable derivatives and protocols and for the employed experimental tools and methods. By using a combined scanning probe (AFM and STM) and spectroscopic methodology (XPS, XAS and XMCD) we show that Gd4M8 derivatives (with M=Zn2+, Ni2+) are robust molecular units which preserve their electronic, magnetic and thermodynamic properties when deposited on a metallic surface. Namely we measured entropy variation ΔS=[S(6T)-S(0T)] exceeding 8R (20 J Kg-1 K-1) at 4K in isolated Gd4Ni8 molecules dispersed on Au(111) surface and show a viable route to exploit large magnetocaloric effect at single molecule level.