Mühlbauer, S.; Pfleiderer, C.; Böni, P.; Forgan, E.M.; Brandt, E.H.; Wiedenmann, A.; Keiderling, U.: Intrinsic bulk vortex dynamics revealed by time resolved small angle neutron scattering. Physica B 404 (2009), p. 3231-3234
10.1016/j.physb.2009.07.080
Abstract:
Measurementsofintrinsicvortexlattice(VL)dynamicsinsuperconductorsasforinstanceVLmeltingor Bragg glasstransitionsaretypicallyperformedbye.g.macroscopictransportorsurfacesensitive measurementtechniques.Therefore,usuallythinsuperconductingfilmsareusedformicroscopic measurementsofVLdynamics.Adirectconsequenceofusingthinfilmsisthestronginfluenceof surface effectsanddefects,samplequalityandgeometry.Wesucceededtocombinetimeresolved stroboscopic smallangleneutronscattering(SANS)withanadvanced,timevaryingmagneticfieldsetup allowing toextendthetimewindowforslowdynamicalprocessestotherangeof10msuptoseveral minutes.Thenewresultsdemonstratethatitispossibletoobservedirectlytheintrinsicdynamicsofthe VL inabulkniobiumsinglecrystalonamicroscopicscalewithoutlimitationsduetosurfaceeffects. Field andtemperaturedependentrelaxationtimesoftheVLfrom100to500mscouldbeobservedfor the firsttime,allowingtodirectlymeasuretheVLofthetiltmodulus.Thisnewexperimentaltechnique providesthepossibilitytostudyalsothedynamicalmagneticpropertiesofvariousstronglycorrelated electronsystems.