(Co_xMg_1−x)O nanocondensates by pulsed laser ablation of bulk alloy in air

Abstract

(Co,Mg)O nanocondensates produced by pulsed laser ablation of MgO–CoO solid solution target in air.

(hkl)-Specific defects of MgO–CoO alloy produced by pulsed laser ablation in water

“…1 GPa) for the particles by PLA of alloy powders in water under 6.25 × 10 10 W cm −2 is about half that produced by PLA of an alloy disk in air under a much lower peak power density (1.5 × 10 7 W cm −2 ). 1 This indicates that the particles were significantly relaxed in water, especially for the Mg-rich specimen, despite the higher power density input and severe shock effect in water of the present PLA process.…”

“…2 GPa) and well-developed {100} faces for coalescence as (100) 26.6°twist boundary with a fair coincidence site lattice (CSL), Mg-doped Co 3−δ O 4 spinel also occurred in the Co-rich specimen. 1 Such MgO-Co 1−x O alloyed nanocondensates, with paracrystals hardly arranged as an array along a specific crystallographic habit plane of the rocksalt-or spinel-type host, were found to catalyze the carbonaceous support to form a turbostratic graphene shell upon radiant heating in the PLA process. 1 On the other hand, PLA of MgO powder in water resulted in the formation of rocksalt-type periclase nanoparticles, which tended to have {111} habit planes parallel to the basal layers of lamellar brucite-like flakes more or less rolled as fibers, ribbons and tubes.…”

“…1 Such MgO-Co 1−x O alloyed nanocondensates, with paracrystals hardly arranged as an array along a specific crystallographic habit plane of the rocksalt-or spinel-type host, were found to catalyze the carbonaceous support to form a turbostratic graphene shell upon radiant heating in the PLA process. 1 On the other hand, PLA of MgO powder in water resulted in the formation of rocksalt-type periclase nanoparticles, which tended to have {111} habit planes parallel to the basal layers of lamellar brucite-like flakes more or less rolled as fibers, ribbons and tubes. 12 Such periclase nanoparticles were also found to nucleate at the edge of the lamellae and/or brucite flakes despite their chiral rolling.…”

“…The rocksalt-type (Co x Mg 1−x )O particles produced by PLA of bulk M9C1, M5C5 and M1C9 alloys in air showed the surface preference {100} > {110} > {111} ~{021} ~{013} ~{311}. 1 By contrast, the present (Co x Mg 1−x )O particles produced by PLA of powdery M9C1, M5C5, M1C9 alloys and Co 1−x O in water have a rather rough surface except M9C1 which showed welldeveloped {100} faces with {110} edges. This indicates that both the Mg/Co ratio and hydrogenation significantly affect the crystal shape of the rocksalt-type oxide.…”

“…The motivation of this research is to fabricate hydrogenated (Mg x Co 1−x )O protoxide and Mg-doped Co 3−δ O 4 spinel via a dynamic pulsed laser ablation (PLA) route in water regarding the (hkl)-specific defects of the particles, in particular the paracrystalline distribution of defect clusters following specific crystallographic planes and the special grain boundary of the spinel phase, which did not occur by conventional heating/annealing or PLA of metal oxides in air as summarized in our inter-related work 1 or by natural occurrence.…”