Canted ferrimagnetism in the distorted double perovskite La 3 Mn 2 NbO 9 Diana M. Arciniegas Jaimes a, * , Valeria C. Fuertes b , M. Cecilia Blanco c , Germ  an Tirao a , Silvina Limandri a , Vivian M. Nassif d , Gabriel J. Cuello e , Alejandro Rodríguez f , Edilso Reguera f , Raúl E. Carbonio b, ** a IFEG (CONICET), Universidad Nacional de C ordoba, Facultad de Matem atica, Astronomía, Física y Computaci on. Av. Medina Allende S/n, Ciudad Universitaria, 5000, C ordoba, Argentina b INFIQC (CONICET), Universidad Nacional de C ordoba, Facultad de Ciencias Químicas, Departamento de Fisicoquímica. Haya de La Torre Esq. Medina Allende, Ciudad Universitaria, X5000HUA, C ordoba, Argentina c CICTERRA (CONICET), Universidad Nacional de C ordoba. Av. V elez S arsfield 1611, Ciudad Universitaria, X5016GCA, C ordoba, Argentina d University Grenoble Alpes, CNRS, Grenoble INP, Institut N eel, 38000, Grenoble, France e Institut Laue-Langevin (ILL), 38000 Grenoble, France f Instituto Polit ecnico Nacional, CICATA-Legaria, Calzada Legaria 694, CP 11500 Mexico City, Mexico article info Article history: Received 6 June 2020 Received in revised form 31 August 2020 Accepted 2 September 2020 Available online 10 September 2020 Keywords: Double perovskite Magnetic measurements X-ray emission spectroscopy X-ray photoelectron spectroscopy Canted ferrimagnetism abstract The synthesis, structural characterization, and magnetic properties of La 3 Mn 2 NbO 9 double perovskite are reported. The crystal structure has been refined by X-ray and neutron powder diffraction data in the monoclinic space group P2 1 /n. The Mn 2þ , Mn 3þ and Nb 5þ cations are distributed at the 2d and 2c Wyckoff sites, with a high cation order degree in the latter, mainly occupied by Mn 2þ /Mn 3þ . The Mn 3þ presence was established from X-ray Emission Spectroscopy and X-ray Photoelectron Spectroscopy. Rietveld re- finements of powder neutron diffraction data show that at room temperature the cell parameters are a¼ 5.6063(3) Å, b¼ 5.8155(3) Å, c¼ 7.9877(2) Å y b¼ 89.89(1)  . Magnetization measurements indicate the presence of ferromagnetic and antiferromagnetic interactions with T C ~19 K and T N ~11 K, respec- tively, with a magnetic cell of symmetry G 1 (A g ). The analysis of the neutron data suggests a canted ferrimagnetic spin structure where an antiferromagnetic unit-cell in a and c axis, and ferromagnetic in b axis with a propagation vector k¼ (0 ½ 0) was used. The effective magnetic moment obtained experi- mentally is m eff ¼ 5.50 m B /mol Mn 2þ/3þ , slightly lower than the theoretical one for spin only (5.83 m B ). © 2020 Elsevier B.V. All rights reserved. 1. Introduction Perovskites are very interesting due to the important applica- tions in catalysis [1], piezoelectricity [2], magnetism [3], magne- toresistance [4], among others [5e7]. The general formula of a simple perovskite is ABO 3 and is a highly flexible structure because most of the elements of the pe- riodic table can be accommodated in the cuboctahedral A and/or octahedral B sites [8]. The structure of a cubic ideal perovskite can be seen as a 3D array of BO 6 octahedra connected by the vertexes, with the cuboctahedral A ion surrounded by 8 BO 6 octahedra. Usually the B site is occupied by a transition metal ion and the A site is normally occupied by an alkaline or alkaline earth ion, but a smaller ion, like a lanthanide, can also be accommodated in this site [9]. Though, some distortions can arise if the A ion is too small [10]. The common distortions are cation displacement within the BO 6 octahedra and distortions and tilting of these octahedra. When two ions, B and B’, are located on two different crystal- lographic B sites, a double perovskite, with general formula A 2 BB’O 6 [11] is obtained where B and B’ ions can be completely or partially ordered among the two different sites. Ordering of the B and B’ cations is observed when there is a large differences of size (Dr> 0.20 Å) and/or charge (greater than 2) between them [12]. The magnetic properties are largely affected by the nature of the B and B’ cations, due to the interactions between them. Consequently the order-disorder of B and B’ cations strongly affects the magnetic * Corresponding author. ** Corresponding author. E-mail addresses: dmarcini@gmail.com, diana.arciniegas@unc.edu.ar (D.M. Arciniegas Jaimes), rcarbonio@unc.edu.ar (R.E. Carbonio). Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: http://www.elsevier.com/locate/jalcom https://doi.org/10.1016/j.jallcom.2020.157018 0925-8388/© 2020 Elsevier B.V. All rights reserved. Journal of Alloys and Compounds 854 (2021) 157018