Concepts of the Global South

Where and what is the Global South? If you ask people on the street, many would probably not have the faintest idea. In everyday parlance and mass media, Global South has hardly become a household term. In academic and (global) policy circles, though, the term is used with much more gusto. Politicians refer to it. The United Nations organize their statistical data in accordance with the term. Academics write books about it - or, as in our case, explicitly include the term in the name of a research center: Global South Studies Center (GSSC). But what does the term entail? Who uses it and why? And what are the implications of marking distinctions between the Global South and the Global North? We thought it relevant to address these questions in more detail – after all, we work for a recently established research institute featuring the term in its name. Accordingly, we asked a number of academics, journals and academic institutions to reflect on the term. In this online issue, we share their various perspectives and critical reflections on the notion of the Global South – see also a short discussion on a number of YouTube videos we have included.

Global Modernities and the (Re-)Emergence of Ghosts

Are ghosts modern? It seems that modernization and spirituality do not contradict each other in most parts of the world. Animist beliefs and ghost rituals often form part of people’s everyday lives vis-à-vis a globalized economy. For them, the unpredictable forces of ‘the market’ correspond with the elusive world of spectral entities. Facing economic risk, flexibility, and precarity, people address the ghosts for protection and luck. This issue of “Voices” will explore the interplay of economic and ritual practice, of everyday uncertainties and ghostly agency, of emerging modernities and (re-)emerging spiritualities.

Neutron Scattering Studies on Complex Magnetic Structures in Magnetoelectric Materials

In this thesis, the magnetic properties of four transition-metal oxides are presented. Their multiferroic and magnetoelectric phases have been investigated by means of different neutron scattering techniques. The materials TbMnO3 and MnWO4 belong to the group of spin-induced multiferroics. Their ferroelectric polarization can be explained by the inverse DzyaloshinskiiMoriya interaction. Another common feature of both materials is the presence of subsequent magnetic transitions from a spin-density wave to a spin spiral. The features of the phase transitions have been studied in both materials and it could be shown that diffuse magnetic scattering from the spin spiral is present even in the ordered spin-density wave phase. The excitation spectrum in the multiferroic phase of TbMnO3 was investigated in detail and a comprehensive dataset was obtained using time-of-flight spectroscopy. A spin-wave model could be obtained which can quantitatively describe the full dispersion. Furthermore, the polarization of the zone-center excitations could be derived which fit well to data from inelastic neutron spectroscopy and infrared spectroscopy. With the combination of spherical neutron polarimetry and a poling of the sample by an electric field, it was possible to observe the chiral magnetic component of the magnetic excitations in TbMnO3 and MnWO4. The spin-wave model for TbMnO3 obtained in this thesis is able to correctly describe the dispersion of this component. The double tungstate NaFe(WO4)2 is isostructural to the multiferroic MnWO4 and develops a complex magnetic phase diagram. By the use of neutron diffraction techniques, the zero-field structure and high-field structures in magnetic field applied along the b-axis could be determined. The data reveal a direct transition into an incommensurate spin-spiral structure. The value of the incommensurability is driven by anharmonic modulations and shows strong hysteresis effects. The static and dynamic properties in the magnetoelectric spin-glass phase of Ni0.42Mn0.58TiO3 were studied in detail. The spin-glass phase is composed of short-ranged MnTiO3 and NiTiO3-type order. The antiferromagnetic domains could be controlled by crossed magnetic and electric fields, which was visualized using spherical neutron polarimetry. A comprehensive dataset of the magnetic excitations in the spin-glass phase was collected. The dataset revealed correlations in the hexagonal plane which are only weakly coupled along the c-axis. The excitation spectra could be simulated by taking into account the MnTiO3-type order.