Canted ferrimagnetism in the distorted double perovskite La3Mn2NbO9

M. CECILIA BLANCO; VIVIAN M. NASSIF; EDILSO REGUERA; VALERIA C. FUERTES; SILVINA LIMANDRI; ALEJANDRO RODRÍGUEZ; VALERIA C. FUERTES; SILVINA LIMANDRI; ALEJANDRO RODRÍGUEZ; DIANA M. ARCINIEGAS JAIMES; GERMÁN TIRAO; GABRIEL J. CUELLO; RAÚL E. CARBONIO; DIANA M. ARCINIEGAS JAIMES; GERMÁN TIRAO; GABRIEL J. CUELLO; RAÚL E. CARBONIO; M. CECILIA BLANCO; VIVIAN M. NASSIF; EDILSO REGUERA

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Año: 2020 vol. 854 p. 157018 - 157026

0925-8388

The synthesis, structural characterization, and magnetic properties of La3Mn2NbO9 doubleperovskite are reported. The crystal structure has been refined by X-ray and neutron powderdiffraction data in the monoclinic space group P21/n. The Mn2+, Mn3+ and Nb5+ cations aredistributed at the 2d and 2c Wyckoff sites, with a high cation order degree in the latter,mainly occupied by Mn2+/ Mn3+. The Mn3+ presence was established from X-ray EmissionSpectroscopy and X-ray Photoelectron Spectroscopy. Rietveld refinements of powder neutrondiffraction data show that at room temperature the cell parameters are a= 5.6063(3) Å, b=5.8155(3) Å, c= 7.9877(2) Å y β= 89.89(1)º. Magnetization measurements indicate thepresence of ferromagnetic and antiferromagnetic interactions with TC ~ 19 K and TN ~ 11 K,respectively, with a magnetic cell of symmetry Gamma1(Ag). The analysis of the neutron datasuggests a canted ferrimagnetic spin structure where an antiferromagnetic unit-cell in a and caxis, and ferromagnetic in b axis with a propagation vector k= (0 ½ 0) was used. Theeffective magnetic moment obtained experimentally is μeff = 5.50 μB/mol Mn2+/3+, slightlylower than the theoretical one for spin only (5.83 μB).