14975-42-9Relevant articles and documents
Ordered olivine-type lithium-cobalt and lithium-nickel phosphates prepared by a new precursor method
Koleva, Violeta,Zhecheva, Ekaterina,Stoyanova, Radostina
, p. 4091 - 4099 (2010)
Single phases of olivine-type LiCoPO4 and LiNiPO4 were synthesized by thermal treatment of homogeneous lithiummetal-phosphate- formate precursors obtained by freeze drying of aqueous solutions of the corresponding metal formates and LiH2PO4. The structure, thermal behavior, and morphology of the precursors were studied by IR spectroscopy, DTA, and SEM. Cobalt and nickel phosphate-formate precursors have a composition LiMHx(PO4)(HCOO)x-yH 2O, where the formate and phosphate groups are mainly deprotonated. For the Co precursor the formate and phosphates ions are randomly coordinated to both Co and Li cations, for the Ni precursor there is a preferential coordination of the formate and phosphate ions around the Ni2+ and Li+ ion, respectively. Thermal treatment of the precursors yields single phases of olivine-type LiCoPO4 at 450 °C and LiNiPO4 at 700 °C. Structural analysis evidences that both LiCoPO4 and LiNiPO4 have an ordered olivine-type structure without any Li to M disorder between the metal positions and lithiurm deficiency. The effect of the freeze-dried solution concentration and annealing temperature on the structure, crystallite size, and morphology of LiCoPO4 and LiNiPO4 has been discussed. The morphology of the cobalt and nickel phospho-olivines comprises isometric particles with mean sizes of 190 and 380 nm, respectively.
Magnetic structure of Ni(DCOO)2(D2O)2
Jorgensen, Mads R. V.,Christensen, Mogens,Schmokel, Mette S.,Iversen, Bo B.
, p. 1441 - 1446 (2011)
Ni(HCOO)2(H2O)2 is a structurally simple coordination polymer showing interesting magnetic phase transitions at low temperature (B and 1.3 μB, and the temperature dependence of the magnetic sublattices is quite different. One of the sublattices shows the expected temperature behavior of an antiferromagnetic compound whereas the other sublattice follows a Brillouin like function with a slowly increasing magnetization below the Neel temperature.
Mechanosynthesis of multiferroic hybrid organic-inorganic [NH4][M(HCOO)3] M = Co2+,Mn2+,Zn2+,Ni2+, Cu2+ formate-based frameworks
Bersani, Danilo,Calestani, Davide,Cugini, Francesco,Gemmi, Mauro,Griesi, Andrea,Orlandi, Fabio,Righi, Lara,Solzi, Massimo,Vit, Valentina
supporting information, (2021/12/23)
The family of compounds with formula [NH4][M(HCOO)3], with M a divalent D-metal, is characterized by porous frameworks hosting NH4+ cations exhibiting at low temperature a spontaneous ferroelectric polarization. The presence of magnetically active divalent metal determines the occurrence of antiferromagnetic ordering below 30 K opening the avenue for a rational formulation of a new class of multiferroic materials. We demonstrate that this intriguing class of compounds can be synthetized with a mechanochemical approach. This novel route of synthesis was applied to the series [NH4][M(HCOO)3] with M= Cu2+, Co2+, Mn2+, Zn2+ and Ni2+ using as reactants ammonium formate and the corresponding di-hydrated metal formates. The milling duration of the process correlates with the thermal stability of the di-hydrated metal formates indicating that the first step of the mechanosynthesis process is represented by the removal of water molecules. The characterizations of the final products indicate the presence of single phase [NH4][M(HCOO)3] compounds with an excellent degree of crystallinity.
Dinuclear and polymeric (μ-formato)nickel(II) complexes: Synthesis, structure, spectral and magnetic properties
Matelková, Kristína,Bo?a, Roman,Dlháň, ?ubor,Herchel, Radovan,Moncol, Ján,Svoboda, Ingrid,Ma?lejová, Anna
, p. 45 - 53 (2015/05/05)
Two (μ-formato)nickel(II) complexes [Ni2(HCOO)(bz)8(H2O)2](HCOO)3·4H2O (1) and [Ni(tren)(HCOO)]ClO4·H2O (2) were synthesized and characterized by spectroscopic methods. The structure of complexes has been determined by X-ray crystallography. The formato ligand bridges the Ni(II) central atoms forming a dinuclear cation in 1 and a polymeric cationic chain in 2, respectively. The coordination environment of Ni(II) atom is nearly octahedral. Based upon the magnetic data, these two compounds display an exchange interaction of the antiferromagnetic nature along with the zero-field splitting. The results from magnetic analysis of 1 and 2, namely the isotropic exchange constants and the zero-field splitting parameters were further confirmed and studied by DFT method using at B3LYP/def2-TZVP and by CASSCF/NEVPT2, respectively.
