Comment on "Spin crossover in (Mg,Fe)O : A Mossbauer effect study with an alternative interpretation of x-ray emission spectroscopy data"

In a recent paper, Kantor presented Mossbauer spectroscopy data on the pressure dependence of the Fe spin state in Mg1-xFexO [Phys. Rev. B 73, 100101(R) (2006)] and found that the transition was completed at significantly higher pressures than what had been found by x-ray emission spectroscopy (XES) studies. In order to account for the discrepancy, the authors reanalyzed the XES spectra using a simple spectral decomposition and achieved good agreement for the two types of data. In this paper, we show that the proposed alternative analysis of the XES spectra is inadequate, prove that previous XES work had correctly identified the low-spin state at the highest pressures, and provide a complete reanalysis of the XES data

Comment on "Spin crossover in (Mg,Fe)O: A Mossbauer effect study with an alternative interpretation of x-ray emission spectroscopy data"

In a recent paper, Kantor presented Mossbauer spectroscopy data on the pressure dependence of the Fe spin state in Mg1-xFexO [Phys. Rev. B 73, 100101(R) (2006)] and found that the transition was completed at significantly higher pressures than what had been found by x-ray emission spectroscopy (XES) studies. In order to account for the discrepancy, the authors reanalyzed the XES spectra using a simple spectral decomposition and achieved good agreement for the two types of data. In this paper, we show that the proposed alternative analysis of the XES spectra is inadequate, prove that previous XES work had correctly identified the low-spin state at the highest pressures, and provide a complete reanalysis of the XES data

Synthesis, magnetochemistry, and spectroscopy of heterometallic trinuclear basic trifluoroacetates [Fe2M(μ3-O)(CF3COO)6(H2O)3]·H2O (M = Mn, Co, Ni)

Three new mu(3)-oxo(trifluoroacetato) complexes [(Fe2MII)-M- III(mu(3)-O)(CF3COO)(6)(H2O)(3)].H2O [M = Mn (1), Co (2), Ni (3)] have been prepared. Compounds 1 and 2 crystallize in the monoclinic space groups C2/c [a = 22.002(5), b = 13.647(3), c = 24.767(4) Angstrom, beta = 98.23(3)degrees] and C2/m [a = 21.426(4), b = 15.100(2), c = 14.815(3) Angstrom, beta = 117.99(2)degrees], respectively. The coordination spheres of the metal ions are essentially octahedral, with the Fe-O distances [1.870(5) Angstrom] falling in the usual range for these systems. Magnetochemical studies reveal the presence of antiferromagnetic exchange in the isosceles triangular skeletons of the polynuclear species. Application of the isotropic spin Hamiltonian H = -2J(FeM)[SFe1SM + SMSFe2] - 2J(FeFe)[SFe1SFe2] gives the fitting parameters: g(Fe) = g(Mn) = 2.00, J(Fe-Fe) = -56.50(7) and J(Fe-Mn) = -16.23(4) cm(-1) (1), g(mol) = 2.09(1), J(Fe-Fe) = -42.8(3.5) cm(-1), J(Fe-Co) = -17.8(1.4) cm(-1) (2) and g(Fe) = 2.00, g(Ni) = 2.215(2), J(Fe- Fe) = -45.60(1) and J(Fe-Ni) = -16.96(2) cm(-1) (3). A Mossbauer investigation confirms that no electron transfer from Mn-II or Co-II to Fe-III occurs during the syntheses of these complexes. (C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002