Mise en page 1 - Laboratoire National des Champs Magnétiques ...

METALS, SUPERCONDUCTORS... 2009Temperature and magnetic field dependence of domain wall width and periodof Condon domain structure in AgDiamagnetic instability of electron gas in normal metals underquantizing magnetic field and low temperature is a resultof strong electron correlations induced by the magneticfield. It gives rise to a phase transition with formation ofcomplex domain patterns (Condon domains).hysteresis in magnetization curves, existence of persistentcurrents which results in a discontinuity of magnetic inductionalong the interface boundaries of regular domainpatterns. Still, there remain open fundamental questionsrelated to the formation of Condon domain phase. As anexample, the important information about the size of thedomains, the domain wall width and surface energy of theinterface boundaries is still lacking. In our studies [N. Logoboyand W. Joss, Solid State Comm. 149, 2007 (2009)]we offer a way to calculate the expected values of domainwall width and period of the domain structure by means ofmeasurement of the value of the jump of magnetic inductionat the domain wall δB (figure 99 and figure 100).Figure 99: Temperature dependence of the DW width δ (a) andperiod of the domain structure D (b) at the conditions of the experiment[Kramer et al., Phys. Rev. Lett. 95, 267209 (2005)].The solid lines correspond to the theory, the circles are calculatedfrom the temperature dependence of the measured jump of magneticinduction at the interface boundaries.The diamagnetic phase transition has received recentlymuch attention due to a number of unusual phenomena forthe physics of diamagnetism, e.g. formation of complexbranch structures, strong dependence of magnetic phase diagramson Fermi-surface topology, presence of diamagneticFigure 100: Magneticfield dependence of the DW width δ (a)and period of the domain structure D (b) at the conditions of theexperiment [Kramer et al., Phys. Rev. Lett. 95, 267209 (2005)].The solid lines correspond to the theory, the circles are calculatedfrom the temperature dependence of the measured jump of magneticinduction at the interface boundaries.W. JossN. Logoboy (The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel and The Instituteof Superconductivity, Department of Physics, Bar-Ilan University, Ramat-Gan, Israel)72