Nanocrystalline BaCo₃(VO₄)₂(OH)₂ with a kagome lattice of Co(ii) ions: synthesis, crystal structure and magnetic properties

Abstract

We report an initial magnetic study of highly crystalline nanoparticles of the layered-kagome compound BaCo3(VO4)2(OH)2. Quasi-spherical nanoparticles with size in the range of 9-25 nm were elaborated for the first...

Microstructured layered-kagome BaCo3(VO4)2(OH)2 with variable crystallite size: alternative synthetic route and comparison with nanostructured samples

“…4 shows a comparison between the FT-IR and Raman spectra of BaCo 3 -A and those previously reported for the BaCo 3 (VO 4 ) 2 (OH) 2 NPs. 13 In the range of 1000-400 cm −1 , the infrared vibration bands, which can be mainly attributed to V-O and Co-O stretching modes, are highly comparable for both micro-and nanostructured…”

“…As expected from these SEM analyses, the microstructured powders exhibit a very low specific surface of about 2 m 2 g −1 which strongly contrasts with that of 61 m 2 g −1 previously obtained for BaCo 3 (VO 4 ) 2 (OH) 2 NPs. 13 BaCo 3 -A and BaCo 3 -B were then characterized by FT-IR and Raman spectroscopies. Fig.…”

“…Recently, we reported a new soft-chemistry route to quantitatively obtain pure quasi-spherical and highly crystalline nanoparticles (NPs) of BaCo 3 (VO 4 ) 2 (OH) 2 with size in the range of 9-25 nm, by a coprecipitation method at ambient pressure. 13 We have demonstrated that nanostructuring does not affect the crystal structure even at the atomic scale. Magnetic susceptibility data at high temperature (T > 150 K) are consistent with highspin d 7 Co 2+ ions in octahedral environment.…”

“…This compound was therefore identified as a candidate in the search for new quantum magnets with spin-orbit coupling. 13 No superparamagnetic blocking temperature or spin-glass transition were detected above 2 K, yet the magnetic behaviour could be affected by finite-size or surface effects at low temperatures. Very recently, Y.…”

“…The family of divalent transition-metal orthovanadates BaM 3 (VO 4 ) 2 (OH) 2 where M = Co, Ni, Cu has received a good deal of attention in the last two decades, essentially because their crystal structures comprise kagome arrays of magnetic ions. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Kagome compounds are of great interest due to their complex and unusual magnetic behaviour resulting from geometric frustration. 15,16 All three BaM 3 (VO 4 ) 2 (OH) 2 compounds have similar crystal structures which are built up of M 3 O 6 (OH) 2 brucite-like layers.…”