La2SrSc2O7: A-Site Cation Disorder Induces Ferroelectricity in Ruddlesden-Popper Layered Perovskite Oxide

Rational design of ferroelectrics in layered perovskites, like n = 2 Ruddlesden-Popper (RP) phase A3B2O7, has been achieved by the hybrid-improper ferroelectric (HIF) mechanism, in which an electric polarization is induced via a trilinear coupling to nonpolar BO6 octahedral rotation and tilt distortions around crystallographic axes. In the present work, hybrid improper ferroelectricity in n = 2 RP-type La2SrSc2O7 induced by the disordering of Sr2+/La3+ cations on the A-sites in rocksalt ([Sr/La]Rs = 25/75) and perovskite ([Sr/La]Pv = 50/50) layers is demonstrated through experimental and theoretical investigations. The ferroelectric A21am structure (a-a-c+ in Glazer notation) at room temperature and the second-order phase transition to paraelectric Amam structure (a-a-c0) at TC ∼ 600 K are determined by a combination of X-ray and neutron diffraction and optical second harmonic generation. The ferroelectric hysteresis loop measurements prove the switchable electric polarization indicative of ferroelectricity. These results represent an unprecedented example of ferroelectricity in the n = 2 RP family of Ln2AB2O7 with inequivalent Ln3+ and A2+ cations. Combining the abovementioned experimental results with the first-principles calculations, we verify the role of Sr/La distributions in regulating the interlayer rumpling, which, in addition to the structural tolerance factor, is key to controlling the structural distortions of RP phases. The stabilization of the ferroelectric, a-a-c+ distorted structure is a consequence of the disordered Sr/La distribution on the A-sites, which suppresses the rumpling-induced octahedral deformations in competition with the octahedral rotations and thus enables the concurrence of a0a0c+ rotations and a-a-c0 tilts required for the HIF mechanism. This work demonstrates the possibility of altering the crystal symmetry of RP phases through the A-site cation disorder and provides a complementary approach to the rational design of new HIF materials.

Topochemical Synthesis of LiCoF3 with a High-Temperature LiNbO3-Type Structure

A novel perovskite fluoride, Li_xCoF₃, which has an exceptionally low tolerance factor (0.81), has been synthesized via low-temperature lithium intercalation into a distorted ReO₃-type fluoride CoF₃ using organolithium reagents. Interestingly, this reaction is completed within 15 min at room temperature. Synchrotron X-ray diffractometry and optical second harmonic generation at room temperature have revealed that this compound shows a high-temperature LiNbO₃-type structure (space group: R3̅c) involving Li-Co antisite defects and A-site splitting along the c direction. A-site splitting is consistent with the prediction based on hybrid Hartree-Fock density functional theory calculations. Co-L_2,3 edge X-ray absorption spectroscopy, as well as bond valence sum analysis, has verified the divalent oxidation state of Co ions in the lithiated phase, suggesting that its composition is close to LiCoF₃ (x ≈ 1). This compound exhibits a paramagnetic-to-antiferromagnetic transition at 36 K on cooling, accompanied by weak ferromagnetic ordering. The synthetic route based on low-temperature lithiation of metal fluorides host paves the way for obtaining a new LiNbO₃-type fluoride family.

Electronic Origin of Non-Zone-Center Phonon Condensation: Octahedral Rotation as a Case Study

Unstable zone-boundary phonon modes drive atomic displacements linked to a rich array of properties. Yet, the electronic origin of the instability remains to be clearly explained. In this Letter, we propose that bonding interaction between Bloch states belonging to different wave vectors leads to such instability via the pseudo- or second-order Jahn-Teller effect. Our first-principles calculations and representation theory-based analyses show that rotations of anion coordinated octahedra, an archetypal example of zone-boundary phonon condensations, are induced by this bonding mechanism. The proposed mechanism is universal to any non-zone-center phonon condensations and could offer a general approach to understanding the origin of structural phase transitions in crystals.

Environmental impact of amino acids on selenate-bearing hydrocalumite: Experimental and DFT studies

Selenium (Se) radioactive wastes can be disposed through stabilization/solidification (S/S) based on the cementitious matrix on hydration products, where hydrocalumite (Ca₂Al-LDH) is expected to play an important role in the retention of SeO₄^2-. Natural organic matters (NOMs) are known to be a risk to affect the transportation and mobility of undesirable chemical species in the pedosphere which receives the low level radioactive wastes (LLW). In the present work, five amino acids were selected as the simplified models of NOMs in the pedosphere to explore their effects on the stability of Ca₂Al-LDH after immobilized SeO₄^2- under alkaline conditions. As the loading amount of amino acids on Ca₂Al-LDH increasing, release of SeO₄^2- was enhanced in HGly, H₂Asp, and H₂Cys series, while no enhancement was observed in HPhe and HTrp series. Density functional theory (DFT) calculation predicted ion-exchange of amino acids and CO₃^2- with SeO₄^2- in a unit cell of LDH model. The intercalation of Asp^2- and CO₃^2- caused 003 peaks in XRD sharper and d₀₀₃ decreased from 8.15 Å to 7.70 Å which is assigned to Ca₂Al-LDH(Asp, CO₃). In H₂Cys series, the 003 peaks were kept broad and SeO₄^2- was still relatively maintained in LDH which was caused by the lower amounts of intercalated CO₃^2- in the presence of H₂Cys. Amino acids in the interlayer of Ca₂Al-LDH have several possible configurations, where the most stable one is prone to be in a horizontal direction through hydrogen bonds and Ca-O chemical bonds. This provides an insight on the stability of selenate immobilized in hydrocalumite, which can be produced in cement disposing in the pedosphere for a long term of burying. Not only carbonate but also small molecular organic matters like amino acids possibly give environmental impact on the mobility of low level anionic radionuclides in LDH.

Environmental impact of amino acids on the release of selenate immobilized in hydrotalcite: Integrated interpretation of experimental and density-functional theory study

The environmental impact of amino acids on the release of SeO₄^2- immobilized into hydrotalcite (Mg₂Al-LDH) which belongs to the layered double hydroxides (LDHs) family was investigated by experimental study and the observed layer structure of hydrotalcite was verified through density-functional theory (DFT) calculations. Glycine, l-cysteine, and l-aspartic acid, which have smaller molecular sizes, can release SeO₄^2- largely due to intercalation, unstabilization of Mg₂Al-LDH and simple dissolution, while l-tryptophan and l-phenylalanine caused limited SeO₄^2- release due to their larger sizes and aromaticity. XRD patterns for the solid residues after intercalation of amino acids revealed that the layer distance of Mg₂Al-LDH was partially expanded. The main peaks and shoulder features corresponding to d₀₀₃ diffraction were well explained by DFT simulations using glycine as a model: the layer spacing of the main peak is responsible for the remaining SeO₄^2- and singly stacked glycine molecule and the layer spacing of the shoulder peak was well explained by doubly stacked glycine molecules. Hydrogen bonds between amino acids and hydroxyl ions in the metallic layers of Mg₂Al-LDH were responsible for the stable configuration of the intercalated Mg₂Al-LDH. This study indicates potential limitations to the stability of low-level radioactive wastes of ⁷⁹Se in repositories which are affected by smaller molecules of amino acids released through degradation of organic matters in the pedosphere.

Nivolumab with carboplatin, paclitaxel, and bevacizumab for first-line treatment of advanced nonsquamous non-small-cell lung cancer

BACKGROUND

This international, randomized, double-blind phase III study (ONO-4538-52/TASUKI-52) evaluated nivolumab with bevacizumab and cytotoxic chemotherapy as first-line treatment for nonsquamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Between June 2017 and July 2019, this study enrolled treatment-naïve patients with stage IIIB/IV or recurrent nonsquamous NSCLC without sensitizing EGFR, ALK, or ROS1 alterations. They were randomly assigned in a 1 : 1 ratio to receive nivolumab or placebo in combination with carboplatin, paclitaxel, and bevacizumab every 3 weeks for up to six cycles, followed by nivolumab/placebo with bevacizumab until progressive disease or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) assessed by an independent radiology review committee (IRRC).

RESULTS

Overall, 550 patients from Japan, Korea, and Taiwan were randomized; of these patients, 273 and 275 received the nivolumab and placebo combinations, respectively. In the present preplanned interim analysis with a median follow up of 13.7 months, the IRRC-assessed median PFS was significantly longer in the nivolumab arm than in the placebo arm (12.1 versus 8.1 months; hazard ratio 0.56; 96.4% confidence interval 0.43-0.71; P < 0.0001). The PFS benefit was observed across all patients with any programmed death-ligand 1 (PD-L1) expression levels including PD-L1-negative patients. The IRRC-assessed objective response rates were 61.5% and 50.5% in the nivolumab and placebo arms, respectively. The incidence of treatment-related adverse events of grade 3 or 4 was comparable between the two arms; treatment-related adverse events leading to death were observed in five and four patients in the nivolumab and placebo arms, respectively.

CONCLUSION

The TASUKI-52 regimen should be considered a viable new treatment strategy for treatment-naïve patients with advanced nonsquamous NSCLC.

Frequency shift algorithm: Application to a frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters

In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.

Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters

Uniform large transition-edge sensor (TES) arrays are fundamental for the next generation of x-ray space observatories. These arrays are required to achieve an energy resolution ΔE < 3 eV full width at half maximum (FWHM) in the soft x-ray energy range. We are currently developing x-ray microcalorimeter arrays for use in the future laboratory and space-based x-ray astrophysics experiments and ground-based spectrometers. In this contribution, we report on the development and the characterization of a uniform 32 × 32 pixel array with 140 × 30 μm² Ti/Au TESs with the Au x-ray absorber. We report on extensive measurements on 60 pixels in order to show the uniformity of our large TES array. The averaged critical temperature is T_c = 89.5 ± 0.5 mK, and the variation across the array (∼1 cm) is less than 1.5 mK. We found a large region of detector's bias points between 20% and 40% of the normal-state resistance where the energy resolution is constantly lower than 3 eV. In particular, results show a summed x-ray spectral resolution ΔE_FWHM = 2.50 ± 0.04 eV at a photon energy of 5.9 keV, measured in a single-pixel mode using a frequency domain multiplexing readout system developed at SRON/VTT at bias frequencies ranging from 1 MHz to 5 MHz. Moreover, we compare the logarithmic resistance sensitivity with respect to temperature and current (α and β, respectively) and their correlation with the detector's noise parameter M, showing a homogeneous behavior for all the measured pixels in the array.

A six-degree-of-freedom micro-vibration acoustic isolator for low-temperature radiation detectors based on superconducting transition-edge sensors

Dilution and adiabatic demagnetization refrigerators based on pulse tube cryocoolers are nowadays used in many low temperature physics experiments, such as atomic force and scanning tunneling microscopy, quantum computing, radiation detectors, and many others. A pulse tube refrigerator greatly simplifies the laboratory activities being a cryogen-free system. The major disadvantage of a pulse tube cooler is the high level of mechanical vibrations at the warm and cold interfaces that could substantially affect the performance of very sensitive cryogenic instruments. In this paper, we describe the performance of a very simple mechanical attenuation system used to eliminate the pulse-tube-induced low frequency noise of the superconducting transition-edge sensors under development for the instruments of the next generation of infra-red and X-ray space observatories.

Sodium titanium oxide bronze nanoparticles synthesized via concurrent reduction and Na+-doping into TiO2(B)

A mixed valence compound, sodium titanium oxide bronze (NaxTiO2-B), combines intriguing properties of high electric conductivity and good chemical stability together with a unique one-dimensional tunnel crystal structure available for cation storage. However, this compound has not been studied for a long period because of the strongly reductive condition at high temperature required for its preparation, which limits the morphological control such as the preparation of nanocrystals. For the first time in this paper, the topotactic synthesis of nano-sized NaxTiO2-B with high specific surface area (>130 m2 g-1) from TiO2(B) nanoparticles has been demonstrated. The reaction of metastable TiO2(B) with NaBH4 allows carrier electrons to be doped simultaneously with incorporation of Na+ ions into the interstitial sites of the host Ti-O lattice at relatively low temperature. An electrochemical investigation of Li+- and Na+-ion storage behaviors suggests that the incorporated Na+ ions are mainly placed in the 6-fold coordination sites of bronze. In addition, optical measurements including time-resolved transient spectroscopy revealed that the doped electrons in the NaxTiO2-B nanoparticles are predominantly in the Ti3+ state and behave as a small polaron. The pelletized NaxTiO2-B nanoparticles shows a good electronic conductivity of 1.4 × 10-2 S cm-1 at 30 °C with an activation energy of 0.17 eV, which is attributable to the thermal barrier for the polaron hopping.

Structural dynamics of LaVO3 on the nanosecond time scale

Due to the strong dependence of electronic properties on the local bonding environment, a full characterization of the structural dynamics in ultrafast experiments is critical. Here, we report the dynamics and structural refinement at nanosecond time scales of a perovskite thin film by combining optical excitation with time-resolved X-ray diffraction. This is achieved by monitoring the temporal response of both integer and half-integer diffraction peaks of LaVO₃ in response to an above-band-gap 800 nm pump pulse. We find that the lattice expands by 0.1% out of plane, and the relaxation is characterized by a biexponential decay with 2 and 12 ns time scales. We analyze the relative intensity change in half-integer peaks and show that the distortions to the substructure are small: the oxygen octahedral rotation angles decrease by ∼0.3° and La displacements decrease by ∼0.2 pm, which directly corresponds to an ∼0.8° increase in the V-O-V bond-angles, an in-plane V-O bond length reduction of ∼0.3 pm, and an unchanged out-of-plane bond length. This demonstration of tracking the atomic positions in a pump-probe experiment provides experimentally accessible values for structural and electronic tunability in this class of materials and will stimulate future experiments.

Artificial two-dimensional polar metal at room temperature

Polar metals, commonly defined by the coexistence of polar crystal structure and metallicity, are thought to be scarce because the long-range electrostatic fields favoring the polar structure are expected to be fully screened by the conduction electrons of a metal. Moreover, reducing from three to two dimensions, it remains an open question whether a polar metal can exist. Here we report on the realization of a room temperature two-dimensional polar metal of the B-site type in tri-color (tri-layer) superlattices BaTiO₃/SrTiO₃/LaTiO₃. A combination of atomic resolution scanning transmission electron microscopy with electron energy-loss spectroscopy, optical second harmonic generation, electrical transport, and first-principles calculations have revealed the microscopic mechanisms of periodic electric polarization, charge distribution, and orbital symmetry. Our results provide a route to creating all-oxide artificial non-centrosymmetric quasi-two-dimensional metals with exotic quantum states including coexisting ferroelectric, ferromagnetic, and superconducting phases.

Random anion distribution in MS x Se2-x (M = Mo, W) crystals and nanosheets

The group VIb dichalcogenides (MX₂, M = Mo, W; X= S, Se) have a layered molybdenite structure in which M atoms are coordinated by a trigonal prism of X atoms. Ternary solid solutions of MS_xSe_2−x were synthesized, microcrystals were grown by chemical vapor transport, and their morphologies and structures were characterized by using synchrotron X-ray diffraction, Rietveld refinement, DIFFaX simulation of structural disorder, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Double aberration corrected scanning transmission electron microscopy was used to determine the anion distributions in single-layer nanosheets exfoliated from the microcrystals. These experiments indicate that the size difference between S and Se atoms does not result in phase separation, consistent with earlier studies of MX₂ monolayer sheets grown by chemical vapor deposition. However, stacking faults occur in microcrystals along the layering axis, particularly in sulfur-rich compositions of MS_xSe_2−x solid solutions.

Nanosheets exfoliated from single crystals of the group VIb sulfoselenides (MS_xSe_2−x, M = Mo, W) are solid solutions at the atomic level.

Light-Activated Gigahertz Ferroelectric Domain Dynamics

Using time- and spatially resolved hard x-ray diffraction microscopy, the striking structural and electrical dynamics upon optical excitation of a single crystal of BaTiO_{3} are simultaneously captured on subnanoseconds and nanoscale within individual ferroelectric domains and across walls. A large emergent photoinduced electric field of up to 20×10^{6}  V/m is discovered in a surface layer of the crystal, which then drives polarization and lattice dynamics that are dramatically distinct in a surface layer versus bulk regions. A dynamical phase-field modeling method is developed that reveals the microscopic origin of these dynamics, leading to gigahertz polarization and elastic waves traveling in the crystal with sonic speeds and spatially varying frequencies. The advances in spatiotemporal imaging and dynamical modeling tools open up opportunities for disentangling ultrafast processes in complex mesoscale structures such as ferroelectric domains.

Perovskite-Type InCoO3 with Low-Spin Co3+: Effect of In-O Covalency on Structural Stabilization in Comparison with Rare-Earth Series

Perovskite rare-earth cobaltites ACoO₃ (A = Sc, Y, La-Lu) have been of enduring interest for decades due to their unusual structural and physical properties associated with the spin-state transitions of low-spin Co³⁺ ions. Herein, we have synthesized a non-rare-earth perovskite cobaltite, InCoO₃, at 15 GPa and 1400 °C and investigated its crystal structure and magnetic ground state. Under the same high-pressure and high-temperature conditions, we also prepared a perovskite-type ScCoO₃ with an improved cation stoichiometry in comparison to that in a previous study, where synthesis at 6 GPa and 1297 °C yielded a perovskite cobaltite with cation mixing on the A-site, (Sc_0.95Co_0.05)CoO₃. The two perovskite phases have nearly stoichiometric cation compositions, crystallizing in the orthorhombic Pnma space group. In the present investigation, comprehensive studies on newly developed and well-known Pnma ACoO₃ perovskites (A = In, Sc, Y, Pr-Lu) show that InCoO₃ does not fulfill the general evolution of crystal metrics with A-site cation size, indicating that InCoO₃ and rare-earth counterparts have different chemistry for stabilizing the Pnma structures. Detailed structural analyses combined with first-principles calculations reveal that the origin of the anomaly for InCoO₃ is ascribed to the A-site cation displacements that accompany octahedral tilts; despite the highly tilted CoO₆ network, the In-O covalency makes In³⁺ ions reluctant to move from their ideal cubic-symmetry position, leading to less orthorhombic distortion than would be expected from electrostatic/ionic size mismatch effects. Magnetic studies demonstrate that InCoO₃ and ScCoO₃ are diamagnetic with a low-spin state of Co³⁺ below 300 K, in contrast to the case of (Sc_0.95Co_0.05)CoO₃, where the high-spin Co³⁺ ions on the A-site generate a large paramagnetic moment. The present work extends the accessible composition range of the low-spin orthocobaltite series and thus should help to establish a more comprehensive understanding of the structure-property relation.

Low-Temperature Cationic Rearrangement in a Bulk Metal Oxide

Cationic rearrangement is a compelling strategy for producing desirable physical properties by atomic-scale manipulation. However, activating ionic diffusion typically requires high temperature, and in some cases also high pressure in bulk oxide materials. Herein, we present the cationic rearrangement in bulk Mn2 FeMoO6 at unparalleled low temperatures of 150-300 (o) C. The irreversible ionic motion at ambient pressure, as evidenced by real-time powder synchrotron X-ray and neutron diffraction, and second harmonic generation, leads to a transition from a Ni3 TeO6 -type to an ordered-ilmenite structure, and dramatic changes of the electrical and magnetic properties. This work demonstrates a remarkable cationic rearrangement, with corresponding large changes in the physical properties in a bulk oxide at unprecedented low temperatures.

The Effect of Fexofenadine on Pruritus in a Mouse Model (HR-ADf) of Atopic Dermatitis

Fexofenadine, a histamine H1-receptor antagonist, is approved for the treatment of pruritus associated with atopic dermatitis. The effects of fexofenadine on scratching behaviour, and plasma levels of histamine and eotaxin were assessed in a new model of atopic dermatitis. Mice fed a diet low in Mg2+ and Zn2+ (special diet S) were compared with mice on a normal diet (N) or diet S plus fexofenadine HCl for weeks 0-10 (S + F0-10), 0-5 (S + F0-5) or 6-10 (S + F6-10) (seven mice per group). Compared with group N, group S mice showed significantly greater scratching frequency, and plasma histamine and eotaxin concentrations; these three variables were significantly lower in group S + F0-10 than in group S. Scratching frequency increased when fexofenadine was discontinued. Fexofenadine significantly reduced mast cell and eosinophil numbers. Histamine may be important in the pathological changes seen in this model of atopic dermatitis, suggesting that it might aid future development of antihistamines for the treatment of atopic dermatitis.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

PbMn(IV)TeO6: A New Noncentrosymmetric Layered Honeycomb Magnetic Oxide

PbMnTeO6, a new noncentrosymmetric layered magnetic oxide was synthesized and characterized. The crystal structure is hexagonal, with space group P6̅2m (No. 189), and consists of edge-sharing (Mn(4+)/Te(6+))O6 trigonal prisms that form honeycomb-like two-dimensional layers with Pb(2+) ions between the layers. The structural difference between PbMnTeO6, with disordered/trigonal prisms of Mn(4+)/Te(6+), versus the similar chiral SrGeTeO6 (space group P312), with long-range order of Ge(4+) and Te(6+) in octahedral coordination, is attributed to a difference in the electronic effects of Ge(4+) and Mn(4+). Temperature-dependent second harmonic generation by PbMnTeO6 confirmed the noncentrosymmetric character between 12 and 873 K. Magnetic measurements indicated antiferromagnetic order at T(N) ≈ 20 K and a frustration parameter (|θ|/T(N)) of ∼2.16.

Comparison of perioperative and short-term oncological outcomes after single- or multiport surgery for colorectal cancer

AIM

The aim of this retrospective study was to compare the short-term surgical results of single-port surgery (SPS) with those of multiport surgery (MPS) for colorectal cancer.

METHOD

We studied 673 consecutive patients who underwent SPS or MPS for colorectal cancer in our department from January 2008 to December 2013. The operative parameters and oncological outcome were analysed and compared between the SPS and the MPS groups retrospectively.

RESULTS

The SPS and MPS groups did not differ significantly in terms of preoperative evaluation. The median operative time was significantly shorter with SPS than with MPS (176 min vs 193 min; P < 0.001). The two groups did not differ significantly in terms of postoperative complications. Length of hospital stay was significantly shorter with SPS than with MPS (8 days vs 10 days; P < 0.001). Oncological resection was similar in the two groups. The disease-free survival rates at 2 years according to the TNM stage did not differ significantly between the two groups (Stage I, 98.5% vs 94.7%; Stage II, 93.4% vs 90.7%; and Stage III, 70.8% vs 68.4%).

CONCLUSION

Our experience demonstrates that SPS is safe and can provide oncological outcomes equal to those of MPS in patients with colorectal cancer.

Mn2FeWO6 : A new Ni3TeO6-type polar and magnetic oxide

Mn(2+)2 Fe(2+)W(6+)O6 , a new polar magnetic phase, adopts the corundum-derived Ni3TeO6 -type structure with large spontaneous polarization (PS) of 67.8 μC cm(-2), complex antiferromagnetic order below ≈75 K, and field-induced first-order transition to a ferrimagnetic phase below ≈30 K. First-principles calculations predict a ferrimagnetic (udu) ground state, optimal switching path along the c-axis, and transition to a lower energy udu-udd magnetic double cell.