research Essay --

An intense research into the structural, physical and transport properties of perovskite manganites with the ordinary formula of R1-xAxMnO3 (where R-rare earth constituent like La, Pr, Nd, Sm, and A - divalent element like Sr, Ca, Ba, and Pb) has been of recent interest due to colossal magnetoresistance (CMR) discovery1-3.Attempts have been make to control the effective of one electron band width which to begin with governs the magnetic and transport properties of the manganites through doping at the R and A sites4-6. In view of the complexity of the manganites, the knowledge on the relationship between the alloyinsulator (MI) transition and ferromagnetic (FM)paramagnetic (PM) transition in CMR manganite perovskites is of all time increasing due to its potential applications 7-9. The metallic properties of doped manganites such as La1-xSrxMnO3 (LSMO) with large band width are explained employing the double exchange (DE) guess 10-13. It is inferred from the above studies that th e narrow band width is not alone responsible for(p) for the observed MI transition and CMR in manganites like La1-xCaxM...