Магнитные и магнитодиэлектрические свойства Ho-=SUB=-0.5-=/SUB=-Nd-=SUB=-0.5-=/SUB=-Fe-=SUB=-3-=/SUB=-(BO-=SUB=-3-=/SUB=-)-=SUB=-4-=/SUB=-

Abstract

The magnetic and magnetodielectric properties of Ho_0.5Nd_0.5Fe_3(BO_3)_4 ferroborate with the competing Ho–Fe and Nd–Fe exchange couplings have been experimentally and theoretically investigated. Step anomalies in the magnetization curves at the spin-reorientation transition induced by the magnetic field B ║ c have been found. The spontaneous spin-reorientation transition temperature T _SR ≈ 8 K has been refined. The measured magnetic properties and observed features are interpreted using a single theoretical approach based on the molecular field approximation and calculations within the crystal field model of the rare-earth ion. Interpretation of the experimental data includes determination of the crystal field parameters for Ho^3+ and Nd^3+ ions in Ho_0.5Nd_0.5Fe_3(BO_3)_4 and parameters of the Ho–Fe and Nd–Fe exchange couplings.