Ab initio calculations of the crystal field and phonon dispersions in CePd2Al2 and LaPd2Al2

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10411126" target="_blank" >RIV/00216208:11320/20:10411126 - isvavai.cz</a>

Alternative codes found

RIV/61989100:27640/20:10244870 RIV/61989100:27740/20:10244870

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=MgWtNP7oKb" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=MgWtNP7oKb</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-648X/ab7031" target="_blank" >10.1088/1361-648X/ab7031</a>

Result language

angličtina

Original language name

Ab initio calculations of the crystal field and phonon dispersions in CePd2Al2 and LaPd2Al2

Original language description

CePd2Al2 crystallizes in the CaBe2Ge2-type tetragonal structure (P4/nmm, 129) and undergoes a phase transition to the orthorhombic Cmme structure at around 13 K. Its inelastic neutron spectra reveal an additional magnetic excitation that was ascribed to electron-phonon interaction leading to a formation of a new quantum quasi-bound vibron state. We present the first-principles calculations of the crystal field excitations and lattice dynamics calculations of the phonon dispersions to compare with the experimental data. The calculated crystal field energy splitting in CePd2Al2 agrees well with the model used to describe the experimental neutron scattering spectra. The first excited crystal field level moves to higher energies when undergoing the transformation from tetragonal to orthorhombic structure, in agreement with the experiment. The analysis based on calculated elastic constants and lattice dynamics calculations show that in both tetragonal and orthorhombic structures there are no imaginary modes for any q-wave vector within the Brillouin zone, and therefore the lattice structures are stable. The phonon dispersions and density of states are calculated for both crystal structures of CePd2Al2 and its nonmagnetic counterpart LaPd2Al2. The results generally agree well with the experimental data including the high phonon density of states around 12 meV. The phonon density of states is also used to calculate the mean squared displacement, Debye temperature, lattice heat capacity and compared with similar properties of the available experiment.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Physics Condensed Matter

ISSN

0953-8984

e-ISSN

—

Volume of the periodical

32

Issue of the periodical within the volume

23

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

235402

UT code for WoS article

000520462000001

EID of the result in the Scopus database

2-s2.0-85083117606