Optical Fiber Magnetic Field Sensing Technology Based on LaFe2

Rare earth elements (REEs) are crucial for high-tech applications, forming compounds with excellent magnetic properties when combined with other metals and semi-metals. However, heavy REEs, which are primary magnetostrictive materials, are scarce, costly, and difficult to recycle. Therefore, we explored light REE-transition metal compounds, specifically LaFe2, as a cost-effective alternative. Using Vienna ab-inito simulation package (VASP), we calculated the properties of LaFe2 through first-principles methods, employing generalized gradient approximation (GGA) and GGA+U. Our results reveal that LaFe2 is a ferromagnetic conductor with superior magnetism. Experiments on LaFe2-coated sensing units demonstrate its sensitivity to magnetic fields, validating our calculations.