Physical properties of nano-scaled Gadolinium in a Boron Nitride matrix: DFT study

Abstract

This study reports for the first time the synthesis of nano-scaled Gadolinium particles embedded in a chemically inert host matrix of turbostratic Boron Nitride. Such nanoparticles exhibited a ferromagnetic & paramagnetic behaviour at 2 K & above room temperature (300 K) respectively at a Curie temperature slightly higher than the bulk value; T C nano ~298.3 K against T C bulk ~293.2 K. Besides, this slight increase in the Curie temperature, It is to be pointed to that the Temperature magnetization exhibited a peculiar behaviour at the vicinity of 224 K. This latter seems related to the phenomenon highlighted previously by Coey et al. It was hypothesized that the susceptibility diverges at a lower spin-reorientation temperature, close to T SR =225 K, whereby the anisotropy changes sign. It was proposed that the magnetic order between T SR and Curie T C is not truly ferromagnetic, but is akin to the incommensurate order found in Erbium. The atomistic spin dynamics simulations and first-principles DFT+U computations were performed to better understand the underlying magnetic behaviour in general & size dependence specifically. The Curie temperature and size-dependent magnetic characteristics of bulk and nanoscale Gd systems were clarified by these computational investigations. • Gd BN matrix and synthesizing the nanoparticles via a rotary evaporator method. • Gd nanoparticles are prone to oxidation in moist air, which degrades their performance. • Gd nanoparticles were successfully stabilized while retaining their amorphous nature and a particle size of 40–50 nm (as confirmed by TEM). • Explores the enhancement of magnetic and optical properties of gadolinium (Gd) nanoparticles by embedding them in a boron nitride (BN) matrix. • Magnetic measurements revealed a transformation from paramagnetic to ferromagnetic behavior at room temperature (300 K), consistent with the Curie temperature of Gd. • The composite exhibited visible/blue photoluminescence, attributed to Gd emissions, highlighting its potential for optoelectronic applications.