Solvent-induced formation of two gadolinium clusters demonstrating strong magnetocaloric effects and ferroelectric properties

Abstract

Two gadolinium clusters, [Gd₂(H₃L)₂(NO₃)₂](NO₃)₂ (1) and [Gd₃(HL)(H₂L)(NO₃)₄]·C₂H₅OH (2) (H₄L = N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine), were synthesized and characterized with different solvents. The magnetic properties of 1 and 2 were recorded and studied in detail. 1 is a centrosymmetric binuclear Gd₂ cluster, adopting a P space group (point group ), and exhibits a strong magnetocaloric effect (MCE) entropy with −ΔS_m of 27.50 J kg⁻¹ K⁻¹. 2 crystallizes in the Pna2₁ space group (polar point group mm2) through solvent modulation and contains an asymmetric trinuclear Gd₃ cluster. Magnetic and ferroelectric investigations of 2 reveal a large change in the magnetocaloric effect entropy with −ΔS_m of 30.22 J kg⁻¹ K⁻¹, ferroelectric hysteresis and dielectric anomalies.