The perpendicular exchange bias field, $H_{\mathrm{EB}}$, of the magnetoelectric heterostructure ${\mathrm{Cr}}_2{\mathrm{O}}_3(111)/(\mathrm{Co}/\mathrm{Pt}{)}_3$ changes sign after field cooling to below the Néel temperature of ${\mathrm{Cr}}_2{\mathrm{O}}_3$ in either parallel or antiparallel axial magnetic and electric freezing fields. The switching of $H_{\mathrm{EB}}$ is explained by magnetoelectrically induced antiferromagnetic single domains which extend to the interface, where the direction of their end spins controls the sign of $H_{\mathrm{EB}}$. Novel applications in magnetoelectronic devices seem possible.

We report on the observation of the spin Seebeck effect in antiferromagnetic ${\mathrm{MnF}}_2$. A device scale on-chip heater is deposited on a bilayer of ${\mathrm{MnF}}_2$ (110) $(30\mathrm{nm})/\mathrm{Pt}$ (4 nm) grown by molecular beam epitaxy on a ${\mathrm{MgF}}_2$ (110) substrate. Using Pt as a spin detector layer, it is possible to measure the thermally generated spin current from ${\mathrm{MnF}}_2$ through the inverse spin Hall effect. The low temperature (2–80 K) and high magnetic field (up to 140 kOe) regime is explored. A clear spin-flop transition corresponding to the sudden rotation of antiferromagnetic spins out of the easy axis is observed in the spin Seebeck signal when large magnetic fields ($>9\mathrm{T}$) are applied parallel to the easy axis of the ${\mathrm{MnF}}_2$ thin film. When the magnetic field is applied perpendicular to the easy axis, the spin-flop transition is absent, as expected.

Tilting toward two properties: Opposing electronic and symmetry constraints can make it difficult to combine some pairs of material properties in a single crystalline material. Magnetization and electrical polarization are such a pair, but their combination could be useful for applications such as magnetoelectric information storage. Pitcher et al. now show that careful design of chemical substitutions in a layered perovskite are both electrically polar and weakly ferromagnetic at temperatures up to 330 K. Science , this issue p. 420

Magnetoelectric switching of perpendicular exchange bias is observed in a $\mathrm{Co}∕\mathrm{Pt}$ multilayer attached to single crystalline magnetoelectric antiferromagnetic ${\mathrm{Cr}}_2{\mathrm{O}}_3\left(111\right)$ . The exchange bias field $H_{\mathrm{EB}}$ can be set to positive or negative values by applying an electric field $E_{\mathrm{fr}}$ either parallel or antiparallel to the magnetic freezing field $H_{\mathrm{fr}}$ while cooling to below the Néel temperature. Based on this result, the antiferromagnetic spin state can be used as a medium for data storage. The authors propose magnetic random access memory cells and magnetic logic devices, which are purely voltage controlled.

The coexistence of cluster glass with long-range antiferromagnetic order in the relaxor ferroelectric PbFe0.5Nb0.5O3 is elucidated. While the transition at TN=153\,\,K on the infinite antiferromagnetic cluster induces 3m symmetry with large EH2 magnetoelectric response, the disconnected subspace of isolated Fe3+ ions and finite clusters accommodates the cluster glass below Tg=10.6\,\,K with field-induced m$'${} symmetry and EH-type magnetoelectric response. Critical slowing-down, memory and rejuvenation after aging, occurrence of a de~Almeida\char21{}Thouless phase line, and stretched exponential relaxation of remanence corroborate the glass nature.

Room-temperature crystal structure, local ferroelectric, and magnetic properties of the ${\text{Bi}}_{1-x}{\text{Gd}}_x{\text{FeO}}_3$ $\left(x=0.1,0.2,0.3\right)$ polycrystalline samples have been investigated by x-ray diffraction, piezoresponse force microscopy, and magnetometry techniques. Performed measurements have revealed a sequence of the composition-driven structural phase transitions $R3c\to Pn{2}_{1}a$ (occurs at $x\sim 0.1$ ) and $Pn{2}_{1}a\to Pnma$ (takes place within the concentrational range of $0.2<x<0.3$ ). The latter structural transformation is attributed to the substitution-induced suppression of the polar displacements. Gd substitution has been shown to effectively induce the appearance of the spontaneous magnetization, thus indicating a promising way for improving multiferroic properties of antiferromagnetic ${\text{BiFeO}}_3$ .