We have gained a microscopic insight into the phenomenon of double magnetization reversal observed in the $\mathrm{NdFe}{\mathrm{O}}_3$ perovskite compound at compensation temperatures of 6.3 K ($T_{\mathrm{comp}1}$) and 4.3 K ($T_{\mathrm{comp}2}$) through analysis of the evolutions of magnetic moments, magnetic anisotropies, and exchange interactions of Nd and Fe sublattices. This understanding stems from studies involving dc magnetization, neutron depolarization, neutron diffraction, and inelastic neutron scattering (INS) on powder and single-crystal samples. Below 8.6 K, additional (magnetic) Bragg peaks are detected in neutron diffraction patterns, corresponding to the $C_x{F}_z$-type Nd sublattice ordering, which entails C-type antiferromagnetic (AFM) ordering along the $a$ axis and a ferromagnetic (FM) component along the $c$ axis. The FM components ($F_z$) of the $\mathrm{N}{\mathrm{d}}^{3+}$ and $\mathrm{F}{\mathrm{e}}^{3+}$ moments are too diminutive to be quantified accurately via powder neutron diffraction; as single-crystal dc magnetization study estimates the FM component (along the $c$ axis) to be approximately 0.09 ${\mu }_{\mathrm{B}}$ at 2 K. Our INS investigations on single-crystal $\mathrm{NdFe}{\mathrm{O}}_3$ sample have unveiled the relative orientations of the $F_z$ components of the Nd and Fe sublattice moments. The INS spectra are found to be consistent with AFM exchange couplings between the Nd-Nd and Nd-Fe sublattices as well as for a planar anisotropy of Nd spins. At 6.3 K, a complete cancellation of the $F_z$ components of the $\mathrm{N}{\mathrm{d}}^{3+}$ and $\mathrm{F}{\mathrm{e}}^{3+}$ moments results in $T_{\mathrm{comp}1}$, whereas a reversal in the sign of the total magnetic moment below 5 K leads to $T_{\mathrm{comp}2}$ at 4.3 K. The present comprehensive single-crystal INS investigation thus shed light on the microscopic mechanism for magnetization reversal phenomenon. This microscopic understanding of such a distinctive phenomenon has practical implications for design of magnetic memory and spin-resolving devices.

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• Magnetic anisotropy
• Magnetism
• Magnons
• Antiferromagnets
• Neutron diffraction
• Neutron scattering
• Spin wave theory