We report the results of comparative studies on angular dependent interlayer magnetoresistance (MR) in the presence of in-plane magnetic fields for layered Dirac antiferromagnets SrMnBi 2 and EuMnBi 2. For both materials, clear four-fold MR was observed at the lowest temperature as a manifestation of field-induced polarization of the anisotropic valleys. Interestingly, we have found a striking difference in angular dependence at high fields between SrMnBi 2 and EuMnBi 2. As a result of fitting to the empirical formula, we have revealed that EuMnBi 2 shows the anomalous field dependence of anisotropic factor, inconsistent with a simple semi-classical theory. We discuss the impact of Eu spins on the valley-selective interlayer conduction in EuMnBi 2 .
The photon energy dependence of photoion emission from solid films of poly(methyl methacrylate) was measured to investigate the primary steps in radiation induced decomposition following carbon and oxygen 1s electron excitations using monochromatic pulsed-synchrotron radiation. Various ions including the monomer ion were observed. Further it was clearly found that the decomposition depends on the nature of the electronic states created in the excitation process. Excitations of carbon 1s electrons to π* and σ* resonance states at 287.9 eV show remarkable enhancement of the ion emission for CH+ and CH2
+. In the energy region of oxygen 1s electron excitation, the increase of COOCH3
+ ion was not observed due to a fragmentation of the side chain by creating oxygen 1s hole.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.