Although bulk magnetic properties of various antiferromagnets have been vigorously studied since long ago, their properties in the form of thin films, which are more relevant to antiferromagnetic spintronic devices, have not been investigated as much. In this work, we characterized the N eel temperature of Cr 2 O 3 thin films by investigating the temperature dependence of the spin Hall magnetoresistance in Cr 2 O 3 /Pt bilayers. A precise determination of the N eel temperature was made possible by carefully designing the direction of the magnetic anisotropy in Cr 2 O 3 . The results provide a reliable way to determine the N eel temperature of antiferromagnetic thin films.

The interface between a magnetic material and a heavy metal that has a large spin-orbit interaction is at the root of various spin-related phenomena. In this paper, we address the peculiar spin-dependent transport at a Pt/Cr 2 O 3 interface by exploring the origin of the nonlinear anomalous Hall effect (AHE) in Pt/Cr 2 O 3 bilayers. X-ray magnetic circular dichroism (XMCD) measurements show no appreciable magnetic moment at the interface originating from Cr 3d and Pt 5d orbitals, which could be associated with the AHE response. A possible interfacial magnetic moment M at the Pt/Cr 2 O 3 interface, assumed from the detection limit of the XMCD measurements, yields an anomalous Hall conductivity (σ AHE) per unit net magnetic moment (M ), −σ AHE /M, of 0.57 V −1 , which is extraordinary large compared with that for general magnetic materials. Together with first-principles calculations, the results suggest the possibility of an intrinsic AHE in the Pt/Cr 2 O 3 interface that does not rely on the net magnetic moment.

BackgroundThyroid storm (TS) is a fatal disease that leads to multiple organ failure and requires prompt diagnosis. Diabetic ketoacidosis (DKA) is a trigger for thyroid crisis. However, TS and DKA rarely occur simultaneously. Moreover, owing to the rarity of the co-occurrence, the clinical course remains unclear. In this study, we present a case of TS that developed during the follow-up for repeated DKA in a young patient.Case PresentationA 25-year-old man with a history of recurrent DKA was brought to the emergency room frequently with similar symptoms. DKA treatment was initiated, but his tachycardia and disturbance of consciousness did not improve. Further examination of the patient revealed a Burch–Wartofsky Point Scale score of 80 points, consistent with the Japan Thyroid Association criteria. Therefore, DKA coexisting with TS was diagnosed. Antithyroid medication, inorganic iodine, and corticosteroids were then started as treatment for TS, and β-blockers were administered to manage tachycardia. With these treatments, the patient’s health improved and he recovered.ConclusionsIn severe cases of recurrent DKA, the presence of TS should be considered, and early treatment should be initiated before the patient’s condition worsens.

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