Phys. Rev. Lett. 88, 077204 (2002) [4 pages]First-Order Transition in the Spin Dynamics of Geometrically Frustrated Yb2Ti2O7Received 4 September 2001; published 1 February 2002 Using neutron diffraction, 170Yb Mössbauer and muon spin relaxation spectroscopies, we have examined the pyrochlore Yb2Ti2O7, where the Yb3+S′ = 1/2 ground state has planar anisotropy. Below ∼0.24K, the temperature of the known specific-heat λ transition, there is no long range magnetic order. We show that the transition corresponds to a first-order change in the fluctuation rate of the Yb3+ spins. Above the transition temperature, the rate, in the GHz range, follows a thermal excitation law, whereas below, the rate, in the MHz range, is temperature independent, indicative of a quantum fluctuation regime. © 2002 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.88.077204
DOI:
10.1103/PhysRevLett.88.077204
PACS:
75.40.-s, 75.25.+z, 76.75.+i, 76.80.+y
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.