Title :

Selective Metal Exsolution in BaFe2–yMy(PO4)2(M = Co2+, Ni2+) Solid Solutions

Author(s) :

Blazquez-Alcover, Ignacio [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Daviero-Minaud, Sylvie [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
David, Rénald [Auteur]
Filimonov, Dmitry [Auteur]
Huvé, Marielle [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Attfield, J. Paul [Auteur]
Kabbour, Houria [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Mentre, Olivier [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Journal title :

Inorganic Chemistry

Volume number :

54

Pages :

8733-8743

Publication date :

2015

HAL domain(s) :

Chimie/Chimie inorganique

English abstract : [en]

The 2D-Ising ferromagnetic phase BaFe2+2(PO4)2 shows exsolution of up to one-third of its iron content (giving BaFe3+1.33(PO4)2) under mild oxidation conditions, leading to nanosized Fe2O3 exsolved clusters. Here we have ...
Show more >The 2D-Ising ferromagnetic phase BaFe2+2(PO4)2 shows exsolution of up to one-third of its iron content (giving BaFe3+1.33(PO4)2) under mild oxidation conditions, leading to nanosized Fe2O3 exsolved clusters. Here we have prepared BaFe2–yMy(PO4)2 (M = Co2+, Ni2+; y = 0, 0.5, 1, 1.5) solid solutions to investigate the feasibility and selectivity of metal exsolution in these mixed metallic systems. For all the compounds, after 600 °C thermal treatment in air, a complete oxidation of Fe2+ to Fe3+ leaves stable M2+ ions, as verified by 57Fe Mössbauer spectroscopy, TGA, TEM, microprobe, and XANES. The size of the nanometric α-Fe2O3 clusters coating the main phase strongly depends on the yM metal concentration. For M-rich phases the iron diffusion is hampered so that a significant fraction of superparamagnetic α-Fe2O3 particles (100% for BaFe0.5–xCo1.5(PO4)2) was detected even at 78 K. Although Ni2+ and Co2+ ions tend to block Fe diffusion, the crystal structure of BaFe0.67Co1(PO4)2 demonstrates a fully ordered rearrangement of Fe3+ and Co2+ ions after Fe exsolution. The magnetic behaviors of the Fe-depleted materials are mostly dominated by antiferromagnetic exchange, while Co2+-rich compounds show metamagnetic transitions reminiscent of the BaCo2(PO4)2 soft helicoidal magnet.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

ENSCL
Université de Lille
CNRS
Centrale Lille
Univ. Artois

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Matériaux inorganiques, structures, systèmes et propriétés (MISSP)
Oxydes Innovants

Submission date :

2019-09-24T14:35:16Z
2023-01-30T15:48:55Z