We explore the interrelation between crystal structure, magnetism, and magnetodielectric behavior in the spin-cluster compound ${\mathrm{Ba}}_6{\mathrm{Nd}}_2{\mathrm{Fe}}_4{\mathrm{O}}_{15}$. Magnetization measurements indicate the emergence of long-range antiferromagnetic order at $T_{\mathrm{N}}\approx 16\mathrm{K}$, supported by corresponding anomalies in the specific heat. Magnetic isotherms display a field-induced spin-flop transition at critical fields ${\mu }_0{H}_{\mathrm{C}1}$ and ${\mu }_0{H}_{\mathrm{C}2}$. Field-dependent neutron diffraction uncovers an antiferromagnetic ground state characterized by the propagation vector ${\mathit{k}}_1=(1/2,0,0)$ for fields ${\mu }_{0}H<0.6\mathrm{T}$, which transitions to a ferrimagnetic state with ${\mathit{k}}_2=(0,0,0)$ for ${\mu }_{0}H>1.2\mathrm{T}$. In the intermediate field range ($0.6\mathrm{T}<{\mu }_{0}H<1.2\mathrm{T}$), both magnetic vectors exist. Dielectric measurements exhibit a distinct anomaly near $T_{\mathrm{N}}$, alongside a robust magnetodielectric response that persists well above the transition, indicating strong coupling between the Fe tetramer spin clusters and dipolar degrees of freedom. The resulting ${\mu }_{0}H\text{–}T$ phase diagram delineates three magnetic regimes, distinguished by shifts in propagation vectors and corresponding variations in magnetization, thermal, and dielectric properties. Furthermore, temperature-dependent synchrotron x-ray diffraction suggests a subtle magnetostrictive effect near the ordering temperature. These findings highlight the intricate magnetodielectric effect in ${\mathrm{Ba}}_6{\mathrm{Nd}}_2{\mathrm{Fe}}_4{\mathrm{O}}_{15}$ and position it as a promising candidate for magnetodielectric applications.

Close

PrevNext

View figure in article

• Electronic & magnetic properties of clusters
• Magnetic susceptibility
• Magnetism
• Magnetoelastic effect
• Magnetoelectric effect
• Pyroelectricity
• Specific heat
• Dielectric constant measurements
• Neutron diffraction
• Susceptibility measurements
• X-ray diffraction