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4f-levels in rare earth cuprates: Crystal field and exchange interaction
Nekvasil V., Jandl S.b, Cardona M.c, Divis M.d, Nugroho A.A.e,f
a Institute of Physics, Czech Academy of Sciences, Czech Republic
b Département de Physique, Université de Sherbrooke, Canada
c Max-Planck-Institut fur Festkörperforschung, Germany
d Department of Electronic Systems, Charles University, Czech Republic
e Van der WaalsZeeman Instituut, Universiteit van Amsterdam, Netherlands
f Jurusan Fisika Institut Teknologi Bandung, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]Measurements of the infrared transmission spectra up to ∼10 000 cm-1, ab-initio calculations based on the density functional theory and the use of an anisotropic exchange Hamiltonian to describe the magnetic coupling of rare earth (RE)-Cu are new instruments shown in this paper to provide an additional insight into the nature of the 4f splitting in rare earth (RE) cuprates. (i) Sets of the parameters of the crystal field Hamiltonian for trivalent Nd and Sm in regular as well as in Ba-sites in RE1+xBa2-xCu3O6+y are determined; (ii) Nd2CuO4 is found to be an exceptionally suitable system to study the anisotropy of the exchange interaction: Kramers doublet splittings due to the superexchange Cu-Nd interaction, deduced from the intermultiplet transitions spectra, are interpreted in terms of an effective Hamiltonian for the Nd3+ ion expressed in terms of single electron spherical tensor operators up to the sixth order; (iii) it is shown that the defects in Nd2CuO4, Nd2-xGdxCuO4 and Nd2-xCexCuO4, that give rise to satellites in the spectra of 4f excitations, are universal and related to a local lattice deformation associated with a charge inhomogeneity. © 2001 Elsevier Science B.V.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Crystal field Hamiltonians[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Crystal and ligand field, exchange and superexchange,High-Tc superconductors,Light absorption and reflection[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text]M.D. and V.N. gratefully acknowledge the Grant Agency of the Czech Republic for grants nos. 202/00/1602 and 202/99/184 and M.D. gratefully acknowledges the Grant Agency of Charles University for its grant no. 145/2000/B-FYZ.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1016/S0925-8388(01)01141-0[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]