Magnetic Order and Localized Electrons at T=0 Meigan C. Aronson, SUNY at Stony Brook , DMR 0907457

1. Magnetic Order and Localized Electrons at T=0Meigan C. Aronson, SUNY at Stony Brook , DMR 0907457 Most metals have magnetic moments at high temperature, but not all retain them as the temperature is reduced. Hybridization tends to delocalize moment bearing electrons, suppressing their magnetism. Compounds with weak hybridization remain magnetic, and tend to order. We propose a phase diagram that is valid at T=0 that shows explicitly that electronic localization is initially a requirement for stabilizing magnetic order. As the moments become increasingly independent, localization can occur without magnetic order, and via a sudden or discontinuous phase transition.. While this organizing scheme was developed for the f-electron based heavy fermion compounds, it is possible that it has a broader applicability in other classes of compounds with strong electronic correlations. Different phases are possible at zero temperature for moment bearing metals depending on the electron-moment coupling G and magnetic field B. Antiferromagnetic order is found in regions I,II. Spin polarization is strong in II,IV,and a strongly interacting heavy fermion is found in region V. Compounds to the left of the dashed line have localized electrons, which otherwise are included in the Fermi surface when order is present.

2. Magnetic Order and Localized Electrons at T=0Meigan C. Aronson, SUNY at Stony Brook, DMR 0907457 Education: Undergraduate students work closely with postdocs and graduate students in our group to carry out the synthesis and crystal structure determinations that underlie our measurement program. This gives them tangible skills that they can take with them in their future scientific careers. 100% of all undergraduate students who worked in our lab have attended graduate school, and 4 are now physics faculty members. Outreach: The PI has initiated a continuing relationship with the dean of the science faculty at the University of Cologne to advise on issues related to increasing the representation of women in the natural science departments. Akshat Puri Greg Smith Carlos Marques Jed Kistner-Morris