A chemical trend of the exchange couplings in rare-earth-3d transition metal hetero-metal complexes has been determined by the collaboration between the Magnetism Division of IMR and the Prof Ishida group in The University of Electro-communications. They found that the magnetic coupling of V and Cu both decreases with increasing atomic number of rare earth element and the sign of the coupling is opposite between V and Cu. The determination of the chemical trend will contribute as a guiding principle in designing new magnetic compounds. Such experimental evaluation of exchange couplings had been difficult for the time consuming procedure. It has become possible by combining the high performance THz ESR system and the effective model of the analysis, which are developed by Prof. Nojiri of the Magnetism Division. In fact, the experimental time reduces to 1/10 of the ordinal procedure in the new method. Moreover, the accuracy of the parameter has been much improved. Thus the present method will be used in the evaluation of exchange coupling in variety of magnetic systems.
The present result is published in Dalton Transactions Voi.41(2012)13609 and the highlight result illustration is in the back cover.