the pyroxene composition of basaltic rocks from the coloured series and exotic blocks in the neyriz area are discussed. comparison has been made with equivalent rocks from oman. the clinopyroxene compositions are in cognation with trace and rare-earth element analyses which definately confirm the occurrence of three different trends in basic lavas: i-depleted tholeiite, 2-transitional basalt, 3...

The Kondo lattice model with Hund’s ferromagnetic spin coupling is investigated as a microscopic model of the perovskite-type 3d manganese oxide R1−xAxMnO3 where R and A are rare earth element and alkaline earth element, respectively. We take the classical spin limit S = ∞ for the simplicity of the calculation, since the quantum exchange process seems to be irrelevant in the high temperature pa...

Nowadays efficient down conversion for white light emission is mainly based on rare-earth doped phosphors or cadmium-containing quantum dots. Although they exhibit high luminescence efficiency, the rare-earth mining and cadmium pollution have so far led to extremely high environmental cost, which conflicts the original purpose of pursuing efficient lighting. Here, we explore a new strategy to a...

The pyroxene composition of basaltic rocks from the Coloured Series and Exotic blocks in the Neyriz area are discussed. Comparison has been made with equivalent rocks from Oman. The clinopyroxene compositions are in cognation with trace and rare-earth element analyses which definately confirm the occurrence of three different trends in basic lavas: I-Depleted tholeiite, 2-Transitional basal...

Type-I clathrates possess extremely low thermal conductivities, a property that makes them promising materials for thermoelectric applications. The incorporation of cerium into one such clathrate has recently been shown to lead to a drastic enhancement of the thermopower, another property determining the thermoelectric efficiency. Here we explore the mechanism of the incorporation of rare earth...