Was Illinois Debt Disproportionately Penalized by the Market During the COVID-19 Pandemic?

There was much uncertainty and concern during the early days of the pandemic about the finances of state and local governments. Lower-rated bond issuers, like the state of Illinois and some other state and local governments, tend to suffer more from interest rate increases during uncertain times. The authors use a set of publicly available data and find that Illinois bond issuers paid a relatively higher price for their bond issues due to its perceived precarious fiscal position entering the COVID-19-induced economic downturn. </p

Thickness-Dependent Crossover from Charge- to Strain-Mediated Magnetoelectric Coupling in Ferromagnetic/Piezoelectric Oxide Heterostructures

Magnetoelectric oxide heterostructures are proposed active layers for spintronic memory and logic devices, where information is conveyed through spin transport in the solid state. Incomplete theories of the coupling between local strain, charge, and magnetic order have limited their deployment into new information and communication technologies. In this study, we report direct, local measurements of strain- and charge-mediated magnetization changes in the La_0.7Sr_0.3MnO₃/PbZr_0.2Ti_0.8O₃ system using spatially resolved characterization techniques in both real and reciprocal space. Polarized neutron reflectometry reveals a graded magnetization that results from both local structural distortions and interfacial screening of bound surface charge from the adjacent ferroelectric. Density functional theory calculations support the experimental observation that strain locally suppresses the magnetization through a change in the Mn-e_g orbital polarization. We suggest that this local coupling and magnetization suppression may be tuned by controlling the manganite and ferroelectric layer thicknesses, with direct implications for device applications