Elements Of X Ray Diffraction

Soft magnetic composite materials (SMCs)

The diversity and evolution of late-Archean granitoids: Evidence for the onset of “modern-style” plate tectonics between 3.0 and 2.5 Ga

Ferrite nanoparticles (FNPs) have attracted a great interest due to their wide applications in several areas such as biomedical, wastewater treatment, catalyst and electronic device. This review focuses on the synthesis, characterisation and application of FNPs in electronic device with more emphasis on the recently published works. The most commonly used synthesis techniques along with their advantages and limitations are discussed. The available characterisation techniques and their application in electronic materials such as sensors and biosensors, energy storage, microwave device, electromagnetic interference shielding and high-density recording media are briefly reviewed.

Ferrite nanoparticles: Synthesis, characterisation and applications in electronic device

Electrical and magnetic characterization of nanocrystalline Ni–Zn ferrite synthesis by co-precipitation route

Dielectric properties such as dielectric constant (e′) and dielectric loss tangent (tan□δ) of mixed Mn-Zn-Er ferrites having the compositional formula Mn0.58Zn0.37Fe2.05−xErx04 (where itx = 0.2, 0.4, 0.6, 0.8 and 1.0) were measured at room temperature in the frequency range 1–13 MHz using a HP 4192A impedance analyser. Plots of dielectric constant (e′) vs frequency show a normal dielectric behaviour of spinel ferrites. The frequency dependence of dielectric loss tangent (tan δ) was found to be abnormal, giving a peak at certain frequency for all mixed Mn-Zn-Er ferrites. A qualitative explanation is given for the composition and frequency dependence of the dielectric constant and dielectric loss tangent. Plots of dielectric constant vs temperature have shown a transition near the Curie temperature for all the samples of Mn-Zn-Er ferrites. However, Mn0.58Zn0.37Er1.0Fe1.05O4 does not show a transition. On the basis of these results an explanation for the dielectric mechanism in Mn-Zn-Er ferrites is suggested.

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Dielectric behaviour of erbium substituted Mn-Zn ferrites

First Paleoproterozoic ophiolite from Gondwana: Geochronologic–geochemical documentation of ancient oceanic crust from Kandra, SE India

The Proterozoic Eastern Ghats Belt (EGB) along the east coast of India exposes deep segments of the continental crust, and is considered as a deeply eroded remnant of the present-day Himalayan-type setting. The EGB registers crustal growth of the Indian plate on its eastern side. Precambrian sutures in this poly-metamorphosed and multiply-deformed belt are recognized by the presence of ophiolites (containing unequivocal sheeted dykes and plagiogranite), shear zones, ultrahigh-T metamorphism, massif-type anorthosites and more significantly, by the presence of deformed alkaline rocks and carbonatites (DARCs). The southern segment of the EGB, around Kondapalli (Andhra Pradesh), records the entire gamut of processes from Palaeoproterozoic rifting to Grenvillian/Pan-African collision. The first convergence event that operated between 2 and 1.6 Ga is yet to be identified in other parts of the EGB. The mafic and felsic granulites of Kondapalli exhibit trace element characteristics typical of subduction-related magmatic arcs and the Kondapalli Layered Complex (KLC) is construed as an arc-root complex in the deeply eroded Eastern Ghats orogen. We postulate that the evolution of the EGB involved two distinct episodes of convergence, both being initiated by the onset of continental rifting. In our favoured model, the first rifting event at ~ 2.0 Ga along the eastern margin of the Indian plate, initiated the formation of an Atlantic-type continental margin, which was later converted into an Andeantype continental margin by convergent plate motion at ~1.85 Ga. Final culmination by continent-continent collision was possibly completed by 1.55 Ga. The second episode of rifting between 1.5-1.35 Ga, along the eastern margin of the thickened arc crust, facilitated the emplacement of alkaline rocks and carbonatites (ARCs). The exact timing of the Mesoproterozoic basin inversion and conversion of ARCs into DARCs - either during Grenvillian or Pan-African orogeny - remains elusive.

Evolution of the Eastern Ghats Belt, India: A Plate Tectonic Perspective

Electrical conductivity of Ni-Zn-Gd ferrites

Recognition of Palaeoproterozoic subduction-induced continental collision and Mesoproterozoic rifting within the Great Proterozoic Fold Belt (GIPFOB) of India supports the existence of Columbia. The Eastern Ghats Granulite Belt (EGGB) is an important component of the GIPFOB and a key player in models of the configuration of the supercontinent. The southern segment of the EGGB records widespread 1.85–1.7 Ga subduction-related arc magmatism and 1.5–1.35 Ga rift-zone igneous activity. The Kondapalli Layered Complex and associated felsic and mafic granulites show unambiguous subduction-related bulk-rock geochemistries and appear to represent deeply eroded remnants of a Palaeoproterozoic continental-margin magmatic arc. The Kandra Ophiolite Complex (KOC), containing a well-developed sheeted-dike complex and plagiogranite, characterizes new oceanic crust formed in a suprasubduction-zone environment. Internal structures, lithological associations, and bulk-rock compositions indicate that the KOC represents a Roc...

K. Vijaya Kumar

Papers

Dielectric behaviour of erbium substituted Mn-Zn ferrites

First Paleoproterozoic ophiolite from Gondwana: Geochronologic–geochemical documentation of ancient oceanic crust from Kandra, SE India

Evolution of the Eastern Ghats Belt, India: A Plate Tectonic Perspective

Electrical conductivity of Ni-Zn-Gd ferrites

Formation and fragmentation of the Palaeoproterozoic supercontinent Columbia: evidence from the Eastern Ghats Granulite Belt, southeast India