ISSN 1061-3862, International Journal of Self-Propagating High-Temperature Synthesis, 2016, Vol. 25, No. 1, pp. 23–29. © Allerton Press, Inc., 2016. 23 1 INTRODUCTION In the past two decades, perovskite manganites with the general formula R 1–x A x MnO 3 (where R is a rare earth cation and A is doping cation) have been extensively investigated because of their interesting physical properties and potential applications [1–6]. Largely, the motivation for these studies stems from the possible utility of colossal-magnetoresistance (CMR) and magnetocaloric (MC) properties in the perovskite manganites at low field and room tempera- ture [7]. The substitution of the rare earth cations with monovalent cations (Ag + , Na + , K + ) in manganites are of particular interest because it leads to the change not only of the valence of Mn ions, like the divalent ele- ments doping, but also to the A-site cation radius and A-site size disorder and thus of the magnetic and elec- trical behavior [8]. Particularly, silver-doped mangan- ites has been shown to manifest giant MC effect which is comparable to that observed in the best MC materi- als with a maximum at room temperature and possess a high sensitivity of the resistance to a magnetic field at the same temperature [9–11]. Recently, silver doped perovskite manganites have been exploited as new 1 The article is published in the original. materials with tunable Curie temperature (T c ) to be used as heat sources for temperature-controlled mag- netic hyperthermia [12–15]. It has been shown that varying the silver content allows one to tune the T c of these materials to the therapeutic hyperthermia tem- perature range of about 42–48°C. In manganites, there is the possibility of inducing ferromagnetism and metal type conduction by silver doping, substituting lanthanum vacancies in the per- ovskite parent compound LaMnO 3 which is antiferro- magnetic to form stoichiometric manganite with a general formula La 1– x Ag x MnO 3 . Also, ferromag- netism and metal type conduction can be induced by creating lanthanum vacancies along with silver doping to form non-stoichiometric manganite compositions with a general formula La 1– x Ag y MnO 3 (y < x). Ini- tially, although there were doubts of the insertion of silver ions in the perovskite lattice [16, 17], there is now experimental evidence for silver doping in the La- site sublattice of La 1– x MnO 3+ δ [18]. However, the available information in literature on the amounts of silver doping allowable in the La-site sublattice of La 1– x MnO 3+ δ for the crystallization of a pure perovs- kite phase with no secondary phase is rather conflict- ing. While some studies using different synthetic Low-Temperature Solution-Combustion Synthesis and Magneto-Structural Characterization of Polycrystalline La 1 – x Ag y MnO 3 (y ≤ x) Manganites 1 C. O. Ehi-Eromosele a , B. I. Ita a, b , A. Edobor-Osoh a , and F. E. Ehi-Eromosele c a Department of Chemistry, Covenant University, PMB 1023, Ota, Nigeria b Department of Pure and Applied Chemistry, University of Calabar, Calabar, Nigeria c Department of Mechanical Engineering, University of Benin, Benin City, Nigeria e-mail: cyril.ehi-eromosele@covenantuniversity.edu.ng Received September 16, 2015 Abstract—Silver is known to be a highly mobile (low-soluble) component in Ag-doped perovskite mangan- ites and hence several non-perovskite phases can exist in silver doped manganite perovskites with most syn- thetic routes making its synthesis to be problematic. In search of soft synthesis route, the low temperature combustion synthesis and magneto-structural studies of polycrystalline La 1– x Ag y MnO 3 (y ≤ x) ceramic man- ganites using glycine as a fuel is reported. The sintered powders were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDAX) analysis, Thermo Gravi- metric Analysis (TGA) and Vibrating Scanning Magnetometer (VSM) measurements. XRD patterns showed formation of mainly single rhombohedral perovskite phase for the La 0.8 Ag 0.15 MnO 3 sample and an admixture of secondary phases with La 0.8 Ag 0.1 MnO 3 and La 0.8 Ag 0.2 MnO 3 samples. The distinct microstructure and higher magnetic properties observed for La 0.8 Ag 0.15 MnO 3 sample compared to the other samples were dis- cussed based on the XRD results. Keywords: solution combustion synthesis, perovskite manganites, magnetic properties DOI: 10.3103/S1061386216010040