The complex magnetoelectric (ME) features of the multiferroic manganites ${R\mathrm{Mn}}_2{\mathrm{O}}_5$ (R: rare earth elements, Bi) are of particular interest due to their giving rise to some fascinating phenomena such as topological ME behaviors. Here we systematically report the magnetic and electric properties of orthorhombic ${\mathrm{ErMn}}_2{\mathrm{O}}_5$ single crystals under DC and pulsed magnetic fields. Based on the anomalies in the experimental data along three crystalline axes, the magnetic field-temperature (H-T) phase diagram of ${\mathrm{ErMn}}_2{\mathrm{O}}_5$ is well established and reveals a significant anisotropy. In the case of H//$a$, at 1.6 K, two magnetic transitions occur at $H_{\mathrm{c}1}\sim 12$ T and $H_{\mathrm{c}2}\sim 30$ T, corresponding to the reversal and saturation of ferroelectric polarizations, respectively. As the temperature increases, $H_{\mathrm{c}1}$ slowly shifts towards lower magnetic fields and eventually becomes vague above 10 K. In contrast, $H_{\mathrm{c}2}$ is insensitive to temperature and remains robust up to 40 K. As a result, two field-induced ME phases are clearly identified above 10 T. For H//$b$, the low-temperature modulated incommensurate phase with weak ferroelectricity (ICM2/X) is gradually suppressed with increasing H, and finally replaced by the commensurate phase with a large polarization (CM/FE1) above 20 T. When the magnetic field is applied along the easy $c$ axis, 1/2- and 3/4-like magnetization plateaus induced by $\mathrm{E}{\mathrm{r}}^{3+}$ spins are observed below 5 K, which were not accessed earlier. The corresponding ferroelectric anomalies are triggered by the $4f\text{−}3d$ interaction between the Er and Mn ions, reflecting the rearrangement of the manganese subsystem. Hence, the successive ME phase transitions are well demonstrated in the low-H region, i.e., ICM2/X → CM/FE1 → ICM3/X′. Intriguingly, the CM/FE1 phase reappears instead of the ICM3/X′ phase above 50 T at low temperatures. Possible origins for all ME phases and magnetization plateaus are discussed. These findings could contribute to an in-depth understanding for the effect of rare earth ions in this family of ${R\mathrm{Mn}}_2{\mathrm{O}}_5$.

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• Antiferromagnetism
• Electric polarization
• High magnetic fields
• Magnetic phase transitions
• Magnetoelectric effect
• Phase diagrams
• Antiferromagnets
• Multiferroics
• Crystal growth
• Magnetization measurements