Crystal defects and spin tunneling in single crystals of Mn12 clusters

نویسندگان

  • J. M. Hernandez
  • F. Torres
  • J. Tejada
  • E. Molins
چکیده

The question addressed in this paper is that of the influence of the density of dislocations on the spin tunneling in Mn12 clusters. We have determined the variation in the mosaicity of fresh and thermally treated single crystals of Mn12 by analyzing the widening of low angle x-ray diffraction peaks. It has also been well established from both isothermal magnetization and relaxation experiments that there is a broad distribution of tunneling rates which is shifted to higher rates when the density of dislocations increases.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Tunneling and EPR linewidths due to dislocations in Mn12 acetate

– We compute the width and shape of the EPR and tunneling resonances due to dislocations in Mn-12 acetate crystals. Uncorrelated dislocations produce the Gaussian shape of resonances while dislocations bound in pairs produce the Lorentzian shape. We stress that the uniaxial spin Hamiltonian together with crystal defects can explain the totality of experimental data on Mn-12. The discovery of re...

متن کامل

Quantum fluctuations and long-range order in molecular magnets

We review our studies of the effect of transverse fields on the susceptibility and magnetization of single crystals of the prototype single molecule magnet (SMM), Mn12-acetate, and of a new high-symmetry variant, Mn12-acetate–MeOH. SMM single crystals can exhibit long range ferromagnetic order associated with intermolecular dipole interactions. Transverse fields increase quantum spin fluctuatio...

متن کامل

Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12

Electron paramagnetic resonance (EPR) measurements on single crystals of the molecular magnets Fe8 and Mn12 reveal complex nonlinearities in the linewidths as functions of energy eigenstate, frequency, and temperature. Using a density-matrix equation with distributions of the uniaxial anisotropy parameter D, the Landé g factor, and dipolar interactions, we obtain linewidths in good agreement wi...

متن کامل

Defects, Tunneling, and EPR Spectra of Single-Molecule Magnets

We examine theoretically electron paramagnetic resonance (EPR) lineshapes as functions of resonance frequency, energy level, and temperature for single crystals of three different kinds of single-molecule nanomagnets (SMMs): Mn12 acetate, Fe8Br, and the S = 9/2 Mn4 compound. We use a density-matrix equation and consider distributions in the uniaxial (second-order) anisotropy parameter D and the...

متن کامل

1 Crystal defects and spin tunneling in single crystals of Mn 12 clusters

The question addressed in this paper is that of the influence of the density of dislocations on the spin tunneling in Mn 12 clusters. We have determined the variation in the mosaicity of the crystal structure of fresh and thermally treated single crystals of Mn 12 by analyzing the widening of low angle X-ray diffraction peaks. It has also been well established from both isothermal magnetization...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2002