INFLUENCE OF THE SIZE EFFECT ON THE REGULARITIES OF THE STRUCTURE FORMATION IN BIMETALLIC Au-Co NANOPARTICLES

Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов

V.S. Myasnichenko¹  K.G. Savina¹  N.I. Nepsha¹  N.Yu. Sdobnyakov¹  A.D. Veselov¹  S.S. Bogdanov¹  A.Yu. Kolosov¹ 

[1] Tver State University, Tver, Russia;

关键词: molecular dynamics method;    bimetallic nanoparticles;    cobalt;    gold;    size mismatch;    structure formation;    stability;    crystallization temperature;    mixing energy;   

DOI  :  10.26456/pcascnn/2021.13.612

来源: DOAJ

【 摘 要 】

This work studied bimetallic Au-Co nanoparticles of three stoichiometric compositions of various sizes by the molecular dynamics method using the tight-binding potential. The regularities of structure formation are established, their characteristic features are described. In particular, in compositions with 50 at% and 75 at% Au content, multiple small nuclei of local icosahedral symmetry are formed. Crystalline phases prevail only in the Co -25 at% Au composition with an increase in the particle size. Compositions are revealed in which the internal symmetry of a nanoparticle is determined by the presence of one icosahedron or a superstructure of several icosahedrons. The concentration dependences of the mixing energy of a bimetallic Au-Co nanoparticle are calculated. It is shown that there are concentrations of compositions at which bimetallic nanoalloys can exhibit instability in a certain size range. Crystallization temperatures were determined using the caloric curves of the potential part of the internal energy. It was found that the crystallization temperature demonstrates a moderate or significant, depending on the composition as well as growth with an increase in the size of bimetallic Au-Co nanoparticles.

【 授权许可】

Unknown