Investigations of the magnetic and lattice vibrations in CoBr 2 using neutron scattering
نویسندگان
چکیده
Inelastic neutron scattering has been used to investigate both the acoustic phonons and the magnetic excitations in CoBr2. The acoustic phonon dispersion curves were measured in three principal symmetry directions at room temperature. From the initial slopes the sound velocities have been derivated and the elastic constants calculated. The two dimensional nature of the crystallographic structure is apparent in the difference between the sound velocities parallel and perpendicular to the closed packed layers although the difference is less than in other halides. Furthermore, the order parameter of the magnetic lattice was found to be 03B2 = 0.3 a value not inconsistent with that expected for a 3 D Ising model. The magnon dispersion was investigated in the (100) and (001) directions at 5 K. The observed dispersion could be explained using a model containing an isotropic exchange within the ground state doublet of the 4T1 term. Renormalization of the spin waves revealed a strong magnonphonon coupling in the (001) direction. J. Physique 43 (1982) 931-938 JUIN 1982, .
منابع مشابه
ابررساناهای دمای بالا- با دید نوترونها
Neutron scattering is proved to be a vital probe in unveiling the magnetic properties of high temperature superconductors (HTSC). Detailed information about the energy and momentum dependence of the magnetic dynamics of HTSC have been obtained directly by this technique. Over the past decade by improving the crystal growth methods, large and high quality single crystals of HTSC, which are ess...
متن کاملThe Vortex Lattice of a Type II Superconductors Studied by Small Angle Neutron Scattering
In this laboratory work we will study the vortex lattice VL of a type II superconductor using Small Angle Neutron Scattering SANS. The sample is a single crystal of Nb, a superconductor with a Tc = 9.3 K and lower and upper critical fields of μ0Hc1 = 0.18T and μ0Hc2 = 0.4T, respectively. For external magnetic fields between Hc1 and Hc2 the superconductor is in the so-called intermediate state. ...
متن کاملAnalysis of Nonlinear Vibrations of Slightly Curved Tripled-Walled Carbon Nanotubes Resting on Elastic Foundations in a Magneto-Thermal Environment
In this work, nonlocal elasticity theory is applied to analyze nonlinear free vibrations of slightly curved multi-walled carbon nanotubes resting on nonlinear Winkler and Pasternak foundations in a thermal and magnetic environment. With the aid of Galerkin decomposition method, the systems of nonlinear partial differential equations are transformed into systems of nonlinear ordinary differentia...
متن کاملNeutron scattering study of Kondo lattice antiferromagnet YbNiSi3
The Kondo lattice antiferromagnet YbNiSi3 was investigated by neutron scattering. The magnetic structure of YbNiSi3 was determined by neutron diffraction on a single-crystalline sample. Inelastic scattering experiments were also performed on a pulverized sample to study the crystalline electric field (CEF) excitations. Two broad CEF excitations were observed, from which the CEF parameters were ...
متن کاملMagnetic properties of „VO...2P2O7: Two-plane structure and spin-phonon interactions
Detailed experiments on single-crystal ~VO!2P2O7 continue to reveal new and unexpected features. We show that a model composed of two, independent planes of spin chains with frustrated magnetic coupling is consistent with nuclear-magnetic-resonance and inelastic-neutron-scattering measurements. The pivotal role of PO4 groups in mediating intrachain exchange interactions explains both the presen...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2016