Modulation of physico-chemical, magnetic, microwave and electromagnetic properties of nanocrystalline strontium hexaferrite by Co-Zr doping synthesized using citrate precursor sol-gel method

Co-Zr doped SrCoxZrxFe(12-2x)O19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been synthesized by citrate precursor sol-gel method. We have studied the impact of coupled substitution of magnetic Co2+ and non-magnetic Zr4+ for Fe3+ on the morphology, magnetic, microwave and electromagnetic properties of SrCoxZrxFe(12-2x)O19. Characterization of these materials has been done by XRD, FT-IR, EDS, TEM, VSM and Mössbauer spectroscopy techniques. Complex permeability (μ′), complex permittivity (ε′) and reflection loss curves have also been analyzed. XRD analysis indicates the formation of single phase hexagonal ferrites at a low temperature of 800°C. Mossbauer spectra indicates that the dopant ions are located on the tetrahedral 4f1 and octahedral 4f2 sites up to x=0.4, octahedral 12k site and bipyramidal 2b site for x=0.6 and 12k site for x=0.8–1.0. The reflection loss (R.L.) analysis shows that all the ferrites (except x=0.2) have wide absorption bandwidth (R.L.<−10 dB for 2–3.5 GHz) with peaks of 90–99% absorption in 12.4–18 GHz band

Ruptured Landscapes, Sacred Spaces and the Stretching of Landscape Capital

This chapter explores the ruptured landscapes of postcolonial Hill Stations in North India. These Hill Stations experienced massive population movements after independence, when the colonial administrators they were constructed for left and new people moved into the cities. Drawing on ethnographic research with minority Christian communities in contemporary Shimla, I demonstrate how the landscapes generated through the worship of these communities heal the ruptures of history by reweaving the trace of historical action. These ruptured communities are therefore rich generators of landscape capital, but of a radically different kind to that discussed in the extant literature. This calls for a reformulation of the landscape capital concept, from a fixed and limited description of historical processes to a widely applicable concept that does justice to the way that past and present are woven together in living landscapes of worship. Postcolonial Shimla, once Simla, the summer capital of colonial India, presents a wonderful case study for these more general issues. Its landscapes provoke questions about the role of memory and identity in the postcolonial city. The Christian landscapes are in many ways the crux of these discomforting questions, but they also offer answers. Moreover, these answers are not hoarded by a minority group, but rather are implicitly presented, as a sort of cipher, to wider civil society. Through this process, the churchscapes of Shimla are able to heal landscape ruptures and stand as a model for harmonious heritage practice in the contemporary city