Structural stability and uniformity of magnetic Pt13 nanoparticles in NaY zeolite

TY - JOUR

T1 - Structural stability and uniformity of magnetic Pt13 nanoparticles in NaY zeolite

AU - Di Paola, Cono

AU - Pavan, Luca

AU - D'Agosta, Roberto

AU - Baletto, Francesca

PY - 2017/10/28

Y1 - 2017/10/28

N2 - Based on first-principles calculations, the structural stability and magnetic variety of Pt13 nanoparticles encapsulated in a NaY zeolite were investigated. Among 50 stable isomers in the gas phase, due to geometrical constraints, only 1/3 of those clusters can be inserted in the zeolite pores. Based on first-principles calculations, the structural stability and magnetic variety of Pt$_{13}$ nanoparticles encapsulated in a NaY zeolite are investigated. Among 50 stable isomers in the gas phase, due to geometrical constraints, only about 1/3 of those clusters can be inserted in the zeolite pores. Severe structural rearrangements occur depending on whether the solid angle at the Pt vertex bound to the super-cage is larger than 2 sr (i.e., icosahedron). The most relevant example is the structural instability of the icosahedron and, when including van der Walls dispersion forces the opening of the gas phase global minimum towards a new L-shaped cubic wire, otherwise unstable. The total magnetisation of the encapsulated Pt$_{13}$ decreases due to the stabilisation of less coordinated isomers, with the majority of clusters characterised by a total magnetisation of 2 $\mu_B$, while the majority of free clusters exhibits a threefold value. This analysis allows understanding the magnetic behaviour observed in recent experiments through the variety of the isomers which can be accommodated in the zeolite pore.

AB - Based on first-principles calculations, the structural stability and magnetic variety of Pt13 nanoparticles encapsulated in a NaY zeolite were investigated. Among 50 stable isomers in the gas phase, due to geometrical constraints, only 1/3 of those clusters can be inserted in the zeolite pores. Based on first-principles calculations, the structural stability and magnetic variety of Pt$_{13}$ nanoparticles encapsulated in a NaY zeolite are investigated. Among 50 stable isomers in the gas phase, due to geometrical constraints, only about 1/3 of those clusters can be inserted in the zeolite pores. Severe structural rearrangements occur depending on whether the solid angle at the Pt vertex bound to the super-cage is larger than 2 sr (i.e., icosahedron). The most relevant example is the structural instability of the icosahedron and, when including van der Walls dispersion forces the opening of the gas phase global minimum towards a new L-shaped cubic wire, otherwise unstable. The total magnetisation of the encapsulated Pt$_{13}$ decreases due to the stabilisation of less coordinated isomers, with the majority of clusters characterised by a total magnetisation of 2 $\mu_B$, while the majority of free clusters exhibits a threefold value. This analysis allows understanding the magnetic behaviour observed in recent experiments through the variety of the isomers which can be accommodated in the zeolite pore.

KW - magnetism, Pt, nanoparticle, zeolite

U2 - 10.1039/C7NR03533K

DO - 10.1039/C7NR03533K

M3 - Article

SN - 2040-3364

VL - 9

SP - 15658

EP - 15665

JO - Nanoscale

JF - Nanoscale

IS - 40

ER -