Speaker
Description
Ni$^{2+}$-doped calcium-aluminosilicate glasses with gehlenite ($2$CaO-Al$_2$O$_3$-SiO$_2$) composition were prepared with different content of Ni$^{2+}$ ($0.1$, $1.0$, and $3.0$ mol. $\%$). The glasses were prepared by combining solid-state synthesis and conventional melt quenching. The prepared system was studied using X-ray diffraction analysis, differential thermal analysis, and a SQUID magnetometer.
Depending on the Ni$^{2+}$ content, glasses with different colours (from light brown to dark green) were prepared. X-ray diffraction analysis confirmed the amorphous nature of all prepared systems. In the DTA curves of all samples, one exothermic effect was observed with a maximum in the temperature interval ($960$ °C – $984$ °C), which, based on our previous work [1], can be attributed to the crystallization of the gehlenite. The maximum temperature of the crystallization peak decreased with increasing content of Ni$^{2+}$ in the glasses, indicating an increasing tendency to crystallize, and lower heat resistance of doped glasses. The magnetic properties of glasses changed as the Ni$^{2+}$ concentration increased (Ni$^{2+}$ ion is paramagnetic), indicating the incorporation of Ni$^{2+}$ ions into the glass matrix. Magnetization versus external magnetic field dependence at $300$ K indicated that the addition of Ni$^{2+}$ significantly influenced the magnetic properties of gehlenite glasses. First, with increasing Ni$^{2+}$ content, the influence of the diamagnetic component decreases and conversely increases the proportion of the paramagnetic component. In the second row, at low fields, the narrow hysteresis loop was present, indicating the existence of a ferromagnetic component. At $2$ K, only the paramagnetic component of the magnetization is present; however, the influence of this component increases with increasing Ni$^{2+}$ addition. The obtained results are consistent with those of other authors [2] and will be useful in the shaping and further processing of these glasses for magneto-optical applications.
Acknowledgements
The financial support of this work by the projects VV-MVP-24-0456, VEGA 2/0077/24, VEGA 2/0028/21 and VEGA 2/0104/25 is gratefully acknowledged.
References
[1] M. Majerová et al., “Study of thermal properties and crystallization kinetics of Bi-doped 2CaO-Al2O3-SiO2 glasses,” Journal of Thermal Analysis and Calorimetry, vol. 148, no. 4. Springer Science and Business Media LLC, pp. 1533–1541, Oct. 05, 2022. https://doi.org/10.1007/s10973-022-11614-y
[2] S. V. G. V. A. Prasad et al., “Nickel ion—A structural probe in BaO–Al2O3–P2O5 glass system by means of dielectric, spectroscopic and magnetic studies,” Journal of Physics and Chemistry of Solids, vol. 67, no. 12. Elsevier BV, pp. 2478–2488, Dec. 2006. https://doi.org/10.1016/j.jpcs.2006.07.002
