Nonlinear elastic effects in phase field crystal and amplitude equations: Comparison to ab initio simulations of bcc metals and graphene

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F16%3A00464413" target="_blank" >RIV/68081723:_____/16:00464413 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14740/16:00093659

Výsledek na webu

<a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.214105" target="_blank" >https://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.214105</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.93.214105" target="_blank" >10.1103/PhysRevB.93.214105</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Nonlinear elastic effects in phase field crystal and amplitude equations: Comparison to ab initio simulations of bcc metals and graphene

Popis výsledku v původním jazyce

We investigate nonlinear elastic deformations in the phase field crystal model and derived amplitude equation formulations. Two sources of nonlinearity are found, one of them is based on geometric nonlinearity expressed through a finite strain tensor. This strain tensor is based on the inverse right Cauchy-Green deformation tensor and correctly describes the strain dependence of the stiffness for anisotropic and isotropic behavior. In isotropic one-and two-dimensional situations, the elastic energy can be expressed equivalently through the left deformation tensor. The predicted isotropic low-temperature nonlinear elastic effects are directly related to the Birch-Murnaghan equation of state with bulk modulus derivative K' = 4 for bcc. A two-dimensional generalization suggests K'(2D) = 5. These predictions are in agreement with ab initio results for large strain bulk deformations of various bcc elements and graphene. Physical nonlinearity arises if the strain dependence of the density wave amplitudes is taken into account and leads to elastic weakening. For anisotropic deformation, the magnitudes of the amplitudes depend on their relative orientation to the applied strain.

Název v anglickém jazyce

Nonlinear elastic effects in phase field crystal and amplitude equations: Comparison to ab initio simulations of bcc metals and graphene

Popis výsledku anglicky

We investigate nonlinear elastic deformations in the phase field crystal model and derived amplitude equation formulations. Two sources of nonlinearity are found, one of them is based on geometric nonlinearity expressed through a finite strain tensor. This strain tensor is based on the inverse right Cauchy-Green deformation tensor and correctly describes the strain dependence of the stiffness for anisotropic and isotropic behavior. In isotropic one-and two-dimensional situations, the elastic energy can be expressed equivalently through the left deformation tensor. The predicted isotropic low-temperature nonlinear elastic effects are directly related to the Birch-Murnaghan equation of state with bulk modulus derivative K' = 4 for bcc. A two-dimensional generalization suggests K'(2D) = 5. These predictions are in agreement with ab initio results for large strain bulk deformations of various bcc elements and graphene. Physical nonlinearity arises if the strain dependence of the density wave amplitudes is taken into account and leads to elastic weakening. For anisotropic deformation, the magnitudes of the amplitudes depend on their relative orientation to the applied strain.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

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

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Svazek periodika

93

Číslo periodika v rámci svazku

21

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

214105

Kód UT WoS článku

000377299100002

EID výsledku v databázi Scopus

2-s2.0-84974733614