Probing local magnetization in molecular heterometallic Cr2Cu trimer

We have extensively studied the magnetic features of a heterometallic molecular trimer, Cr2Cu. We havecharacterized molecular Cr2Cu by low-temperature ac susceptibility and specific-heat measurements and thisallowed us to determine the microscopic parameters of the spin Hamiltonian. Then, we used x-ray magneticcircular dichroism to selectively probe local symmetries, electronic configuration, orbital, and spin magneticmoments of the magnetic ions. We found that at low temperatures only the ground state S=3/2 is occupied andthe spin of Cu is found opposite to that of Cr in agreement with spin-Hamiltonian calculations.