TY - JOUR

T1 - Study of Co x Pt 1-x nanoalloy formation mechanism via single-source precursors

AU - Filatov, E. Yu

AU - Zadesenets, A. V.

AU - Komogortsev, S. V.

AU - Plyusnin, P. E.

AU - Chepurov, A. A.

AU - Korenev, S. V.

PY - 2019/9

Y1 - 2019/9

N2 - This paper is devoted to the study of formation mechanism of metal solid solutions during the thermolysis of single-source precursors in Co-Pt systems with a wide range of superstructural ordering. It is shown that the thermal decomposition of [Pt(NH 3 ) 4 ][Co(C 2 O 4 ) 2 (H 2 O) 2 ]·2H 2 O salt in helium is critically different from that under hydrogen atmospheres. Thermal degradation under the helium atmosphere is followed by a gradual reduction of platinum and cobalt, and at each thermolysis temperature only one phase is present. At 380 °C an equiatomic Co 0.50 Pt 0.50 solid solution is formed (a = 3.749 (4) Å, Fm-3m space group, V/Z = 13.17 Å 3 , crystallite size: 5-7 nm). When the precursor is decomposed under a hydrogen atmosphere, the process proceeds mainly through the simultaneous reduction of the platinum and cobalt atoms, and at each temperature section two metal phases are present. The formation of the close to equiatomic Co 0.50 Pt 0.50 solid solution (a = 3.782 (4) Å, Fm-3m space group, V/Z = 13.52 Å 3 , crystallite size: 7-9 nm) occurs at 450 °C. The calculations of crystallite sizes are confirmed by transmission electron microscopy data.

AB - This paper is devoted to the study of formation mechanism of metal solid solutions during the thermolysis of single-source precursors in Co-Pt systems with a wide range of superstructural ordering. It is shown that the thermal decomposition of [Pt(NH 3 ) 4 ][Co(C 2 O 4 ) 2 (H 2 O) 2 ]·2H 2 O salt in helium is critically different from that under hydrogen atmospheres. Thermal degradation under the helium atmosphere is followed by a gradual reduction of platinum and cobalt, and at each thermolysis temperature only one phase is present. At 380 °C an equiatomic Co 0.50 Pt 0.50 solid solution is formed (a = 3.749 (4) Å, Fm-3m space group, V/Z = 13.17 Å 3 , crystallite size: 5-7 nm). When the precursor is decomposed under a hydrogen atmosphere, the process proceeds mainly through the simultaneous reduction of the platinum and cobalt atoms, and at each temperature section two metal phases are present. The formation of the close to equiatomic Co 0.50 Pt 0.50 solid solution (a = 3.782 (4) Å, Fm-3m space group, V/Z = 13.52 Å 3 , crystallite size: 7-9 nm) occurs at 450 °C. The calculations of crystallite sizes are confirmed by transmission electron microscopy data.

KW - cobalt

KW - nanoalloy formation

KW - nanoparticles

KW - platinum

KW - powder diffraction

KW - MAGNETIC-PROPERTIES

KW - CO

KW - PREFERENTIAL OXIDATION

UR - http://www.scopus.com/inward/record.url?scp=85065722054&partnerID=8YFLogxK

U2 - 10.1017/S0885715619000162

DO - 10.1017/S0885715619000162

M3 - Article

AN - SCOPUS:85065722054

VL - 34

SP - S27-S31

JO - Powder Diffraction

JF - Powder Diffraction

SN - 0885-7156

IS - S1

ER -