Magnetic properties of single crystalline itinerant ferromagnet AlFe2B2

TL;DR

This study investigates the magnetic and electrical properties of single crystalline AlFe2B2, revealing its itinerant ferromagnetism with a Curie temperature of 274 K and pressure-dependent magnetic transition suppression.

Contribution

It provides comprehensive experimental and theoretical analysis of AlFe2B2's magnetic properties, including growth, characterization, and pressure effects, highlighting its itinerant ferromagnetic nature.

Findings

Curie temperature of 274 K

Pressure suppresses T_C to 255 K at 2.24 GPa

Magnetocrystalline anisotropy constants agree with DFT calculations

Abstract

Single crystals of AlFe$_{2}$B$_{2}$ have been grown using the self flux growth method and then measured the structural properties, temperature and field dependent magnetization, and temperature dependent electrical resistivity at ambient as well as high pressure. The Curie temperature of AlFe$_{2}$B$_{2}$ is determined to be $274$~K. The measured saturation magnetization and the effective moment for paramagnetic Fe-ion indicate the itinerant nature of the magnetism with a Rhode-Wohlfarth ratio $ \frac{M_{C}}{M_{sat}}\approx 1.14$. Temperature dependent resistivity measurements under hydrostatic pressure shows that transition temperature \textit{T$_C$} is suppressed down to 255 K for $p = 2.24$~GPa pressure with a suppression rate of $\sim -8.9$~K/GPa. The anisotropy fields and magnetocrystalline anisotropy constants are in reasonable agreement with density functional theory calculations.