Fe Site Order and Magnetic Properties of Fe1/4NbS2.

Transition-metal dichalcogenides (TMDs) have long been attractive to researchers for their diverse properties and high degree of tunability. Most recently, interest in magnetically intercalated TMDs has resurged due to their potential applications in spintronic devices. While certain compositions featuring the absence of inversion symmetry such as Fe1/3NbS2 and Cr1/3NbS2 have garnered the most attention, the diverse compositional space afforded through the host matrix composition as well as intercalant identity and concentration is large and remains relatively underexplored. Here, we report the magnetic ground state of Fe1/4NbS2 that was determined from low-temperature neutron powder diffraction as an A-type antiferromagnet. Despite the presence of overall inversion symmetry, the pristine compound manifests spin polarization induced by the antiferromagnetic order at generic k points, based on density functional theory band-structure calculations. Furthermore, by combining synchrotron diffraction, pair distribution function, and magnetic susceptibility measurements, we find that the magnetic properties of Fe1/4NbS2 are sensitive to the Fe site order, which can be tuned via electrochemical lithiation and thermal history.

Analyzing emergency call volume, call durations, and unanswered calls during the first two waves of the COVID-19 pandemic compared to 2019: An observational study of routine data from seven bavarian dispatch centres.

Background: The spread of the COVID-19 pandemic and the corresponding implementation of measures such as stay-at-home orders and curfews had a major impact on health systems, including emergency medical services. This study examined the effect of the pandemic on call volumes, duration of calls and unanswered calls to the emergency number 112. Method: For this retrospective, descriptive study, 986,650 calls to seven emergency dispatch centres in Bavaria between January 01, 2019 and May 31, 2021 were analysed. The absolute number of calls and calls per 100,000 inhabitants as well as the number of unanswered calls are reported. The Mann‒Whitney U test was used to compare mean call durations between 2019 and 2020/2021 during several periods. Results: Call volume declined during the pandemic, especially during periods with strict lockdown restrictions. The largest decline (-12.9 %) occurred during the first lockdown. The largest reduction in the number of emergency calls overall (-25.3 %) occurred on weekends during the second lockdown. Emergency call duration increased, with the largest increase (+13 s) occurring during the "light" lockdown. The number of unanswered calls remained at a similar level as before the pandemic. Conclusion: This study showed that the studied Bavarian dispatch centres experienced lower call volumes and longer call durations during the first two waves of the COVID-19 pandemic (up to May 2021). Longer call durations could be the result of additional questions to identify potentially infectious patients. The fact that the number of unanswered calls hardly changed may indicate that the dispatch centres were not overwhelmed during the study period.