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SUMMARY:Neutron scattering studies of ferromagnetic superconductor UGe2 un
 der pressure - Dmitri Sokolov\, University of Edinburgh
DTSTART:20091202T111500Z
DTEND:20091202T121500Z
UID:TALK18676@talks.cam.ac.uk
CONTACT:Michael Sutherland
DESCRIPTION:We present high resolution measurements of the lattice constan
 ts of UGe2 under pressure probed by a novel technique that utilizes Larmor
  precession of polarized neutrons to surpass the resolution of conventiona
 l scattering methods by an order of magnitude. At low\ntemperature UGe2 is
  ferromagnetic up to critical pressure P_C but superconductivity is peaked
  at a lower pressure P_x coinciding with a less well understood transition
  within the ferromagnetic state [1]. In zero pressure we confirm that ther
 e are sharp anomalies in the lattice parameters at both the Curie temperat
 ure T_C and T_x (the characteristic temperature for the same  transition t
 hat occurs at P_x. We find that for pressures of 10 and 12 kbar the sharp 
 anomalies shift to lower temperatures in agreement with the known phase di
 agram. At 10 kbar\, the pressure corresponding to an onset of superconduct
 ivity\, the lattice expansion at the ferromagnetic transition is first ord
 er like and much stronger than in zero pressure. The results indicate a co
 mplex evolution of the electronic structure of UGe2 with  pressure and sug
 gest that the magnetoelastic coupling is strengthened at the pressures at 
 which superconductivity appears\; this  may play an important  role in sta
 bilizing superconductivity.\n\n[1] S. S. Saxena\, et al.\, Nature 406\, 58
 7 (2000)
LOCATION:Mott Seminar Room\, Cavendish Laboratory\, Department of Physics
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