Exploring Ti-doped La(Fe,Si)13 as A promising alternative for phase stability and gas liquefaction applications

La(Fe,Si)13-based alloys have been recently used due to their low cost, and functional applications in magnetocaloric refrigeration, air conditioning, heating systems, and energy conversion. However, enhancing their mechanical performance is essential for practical devices implementation. This improvement can be obtained by incorporating dopants such as Ti, which increases their mechanical properties. In this work, we propose the use of low-Ti doping in the LaFe 11.57 Si 1.43 alloy. These alloys were produced combining electric arc melting and melt spinning, followed by heat treatment at 1100°C for 1 h. La(Fe, Si) 13 crystalline structure, the NaZn 13 -type phase, was identified as the main phase using the X-ray diffraction (XRD) technique. Additionally, a α-Fe secondary phase was detected in all the ribbons. For samples with x= 0.2 and 0.3, the secondary La 2 O 3 and Fe 3 O 4 phases were obtained. The Mössbauer spectra of LaFe 11.57-x Si 1.43 Ti x alloys were fitted at room temperature with a doublet and a singlet associated with the 1:13 phase; and four sextets, one related to the α-Fe site and three related to the α-Fe sites with one, two, and three Si atoms as nearest neighbors, respectively. Two additional sextets were used for samples with 0.2 and 0.3, which were related to the Fe 3 O 4 phase. Using Vibrating Sample Magnetometry (VSM) the Curie temperature [T C ] obtained ranged from 223.25 to 208.33 K, while the magnetic entropy change [ΔS M ] varied from 3.0 to 3.4 Jkg -1 K -1 as x increased from 0 to 0.1 during cooling. For x = 0.1, the 1:13 phase concentration improved regarding the value for x = 0 while other secondary phases appear in the sample with x = 0.2 and = 0.3. Low-Ti doping in the La-Fe-Si material improves its magnetocaloric performance and phase stability while decreasing its transformation temperature. These results highlight the suitability of these systems for gas liquefaction applications utilizing solid-state refrigeration technologies. • La(Fe, Si) 13 alloys were dopped with Ti by using arc furnace, melt spinning and thermal treatment. • LaFe 11.57-x Si 1.43 Ti x alloys exhibit the paramagnetic 1:13 phase at room temperature. • The alloy dopped with x= 0.1 titanium presents an increase of the 1:13 phase. • Magnetic properties decreased for doping concentration x ≥ 0.2 titanium. • For x = 0.1 Ti a big latent heat (> 630 J/kg) was obtained.