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Superconductivity in a nitride of the MAX-phase family was reported by A.D. Bortolozo et al. in Ti2InN (a = 0.3074 nm, c = 1.3975 nm) with a transition temperature of 7.3 K. In this study, we report on Ti2InN MAX phase-based samples (with up to 94 wt.% of Ti2InN) synthesized by several methods, which, unfortunately, did not comply with bulk superconductivity of this compound. The Ti2InN materials were synthesized from Ti2InN precursor powder of 93–95 wt.% purity (obtained by the method proposed by (Bortolozo et al., 2010)) according to the following routes: (1) at 130 bar of N2, leading to 54 wt.% of Ti2InN (a = 0.3076(1), c = 1.4012(5) nm); (2) in a sealed quartz ampoule in Ar, (88.5 wt.% Ti2InN, a = 0.3076(1), c = 1.4012(4) nm); (3) by spark plasma sintering (SPS) in contact with hBN at 45 MPa (94 wt.% Ti2InN, a = 0.3077(7), c = 1.4021(5) nm), and (4) by high quasihydrostatic pressure - high temperature sintering (HP-HT) in contact with hBN at 4 GPa (83.5 wt.% Ti2InN, a = 0.3075(3), c = 1.4017(5) nm). Despite all the manufactured samples demonstrated superconducting behaviour with Tc (onset) near 5 K and the samples prepared by SPS and HP-HT methods were highly dense, a very broad magnetic transition (ac susceptibility) not saturating down to 2 K has been observed. No macroscopic Meissner phase was established and the magnetization was far too weak to evidence bulk superconductivity of the entire sample and hence of Ti2InN. However, a superconducting gap of about 1.2–2.1 mV was derived from point-contact spectroscopy at some areas of HP-HT sintered samples. The dispersed crystalline admixture grains of TiN phase in Ti2InN matrices of our samples or a metallic In-alloy are most probable candidates for the superconducting phase in our materials.

The possibility of synthesizing functional oxide thin films at low temperature via combustion synthesis is analyzed both experimentally and numerically. To this aim, the decomposition of several oxide precursors [copper and cerium acetates, yttrium trifluoroacetate, and In2O3and La0.7Sr0.3MnO3(LSMO) nitrate based precursors] has been analyzed by thermal analysis techniques. It is shown that, although these precursors decompose via combustion when they are in the form of powders, their corresponding films show no evidence of combustion. The reason for this different behavior is clearly revealed with numerical simulations. Thin films will hardly experience combustion because the precursor front extinguishes before reaching the precursor–substrate interface leaving a “cool zone” hundreds of micrometers thick. In contrast, it is argued that thin oxide films can be obtained at temperatures lower than powders because of the enhanced gas transport mechanisms that usually limit the decomposition rate.