The microstructure and magnetic susceptibilities of LaFe11.4Si1.6 compound

The fabrication processes of bulk LaFe13−xSix compounds are usually time-consuming but significantly impact on the microstructural and magnetic properties. High-resolution transmission electron microscope (HRTEM) and bulk magnetometry measurements are employed to study the microstructural and magnetic properties of LaFe11.4Si1.6 compound. The crystallization status frozen by quenching is uncovered completely through the HRTEM observations. Besides of crystalline structure, both noncrystalline and nanocrystalline structures are observed. This behavior may originate from the difficulty in the combining capacity between Fe and La. The magnetic measurements reveal that dc and ac inversed susceptibilities are not consistent under strong and weak applied magnetic fields. The behaviors of magnetic susceptibilities deviate from the Curie–Weiss law under weak applied magnetic fields.

Research highlightsNaZn13-type LaFe13−xSix compounds have attracted considerable attentions, though their properties have not be understood entirely yet. Lack of microstructural information is an obstacle of making new progress. In this paper, we systemically study the microstructural and magnetic properties of LaFe11.4Si1.6 compound by high-resolution transmission electron microscope and bulk magnetometry measurements. The correlations between the microstructural and magnetic properties are uncovered. Besides of crystalline structure, both noncrystalline and nanocrystalline structures are observed. The magnetic measurements reveal that the inverse susceptibilities deviate from Curie–Weiss law dramatically, and even not coincide with each other in different low applied magnetic fields. We give reasonable explanation for the anomalous susceptibility behaviors.