Physics Commons^™

Revisiting Galvanomagnetic Effects In Conducting Ferromagnets, Raymond T. Walter, Michel Viret, Surendra Singh, Laurent Bellaiche

Raymond Walter

Diluted Magnetic Semiconductors Based On Sb2àXvxte3 „0.01ïXï0.03., Jeffrey Dyck, Pavel Hájek, Petr LošŤÁK, Ctirad Uher

Jeffrey Dyck

We report on a diluted magnetic semiconductor based on the [formula] tetradymite structure doped with very low concentrations of vanadium (1—3 at. %). The anomalous transport behavior and robust magnetic hysteresis loops observed in magnetotransport and magnetic measurements are experimental manifestations of the ferromagnetic state in these materials. The [formula] exchange between holes and vanadium [formula] spins is estimated from the behavior of the magnetoresistance. A Curie temperature of at least 22 K is observed for [formula] This discovery offers possibilities for exploring magnetic properties of other tetradymite structure semiconductors doped with a wide range of [formula] transition metals.

Effect Of Ni On The Transport And Magnetic Properties Of Co1àXnixsb3, Jeffrey Dyck, Wei Chen, Jihui Yang, Gregory P. Meisner, Ctirad Uher

Jeffrey Dyck

The filled skutterudite compounds based on the binary skutterudite [formula] are currently being investigated for their potential applications as thermoelectric materials. One route to optimization of these compounds is by doping on the Co site. An obvious candidate for an n-type dopant is Ni, since it has one more electron in its valence shell than Co. Up to now, however, only high concentrations of Ni in [formula] have been studied; and the valence of Ni in this compound and its influence on the transport and magnetic properties has been an open question. We present electrical resistivity, thermopower, Hall effect, magnetoresistance, …

The Influence Of Ni On The Transport Properties Of Cosb3, C. Uher, Jeffrey Dyck, W. Chen, G. Meisner, J. Yang

Jeffrey Dyck

The effect of Ni doping on the Co site of the binary skutterudite CoSb3 is investigated. We measured resistivity, Hall effect, magnetoresistance, thermopower, thermal conductivity, and magnetization of a series of samples of the form Co1-xNixSb3 with x in the range x=0 to x=0.01. We find that Ni takes the tetravalent state Ni4+, assumes the d6 electronic configuration for the lower energy non-bonding orbitals, and gives an electron to the conduction band. Ni doping dramatically suppresses the thermal conductivity, changes the temperature dependence of the thermopower, and increases the carrier concentration. Low temperature anomalies in thermopower, Hall coefficient and magnetoresistance …