Galvanomagnetic Properties of NbSi 2
- PDF / 273,811 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 79 Downloads / 244 Views
PROPERTIES OF NbSi 2 ,
U. GOTTLIEBab, 0. LABORDEac, and R. MADARb aCentre de Recherches sur les Tr~s Basses Temp6ratures, CNRS, BP 166, 38042 Grenoble C6dex 9, France, bLaboratoire des Mat6riaux et du G6nie Physique, ENSPG, INPG, BP 46 38402 St. Martin d'Hbres, France CLaboratoire des Champs Magn~tiques Intenses, CNRS-MPI, BP 166, 38042 Grenoble C~dex 9, France
ABSTRACT We present Hall effect and transverse angular magnetoresistance measurements on high quality NbSi2 single crystals. The Hall coefficient RH is varying from -3.5 to -4.5x10-10 m3/C in low magnetic field to -10.5x10-10 m3/C in the high field region. The magnetoresistance shows variations of two orders of magnitude when the field is rotated in the plane perpendicular to the current. For some specific field directions along major crystallographic axes, Ap/p saturates at high magnetic field, indicating the presence of open orbits on the Fermi surface of NbSi 2. INTRODUCTION Despite of the great use of transition metal silicides in microelectronics, their fundamental properties have only scarcely been explored. In the last years, we performed an exhaustive study of the intrinsic properties of the three isostructural and isoelectronic disilicides (hexagonal structure type C40, space group P6222) VSi 2 , NbSi2 and TaSi2 on high quality single crystals [1-3]. In particular we explored the transport properties of these materials. Their resistivity is anisotropic and these results have been confirmed by magnetic susceptibility measurements [4]. We present here the galvanomagnetic properties of NbSi2 measured on high quality single crystals in the temperature range between 4.2 K and 160 K. We measured the magnetoresistance and the Hall effect. The former was measured as a function of the applied magnetic field, of the field angle relative to the crystallographic axis and of the temperature and the later as a function of the magnetic field and of the temperature. EXPERIMENTAL The sample was a piece of single crystal in the form of a small parallelepiped with dimensions of 6 x 3 x 0.14 mm 3 . The sample was oriented, so that the longest dimension was parallel to the a axis, and the shortest parallel to the c axis. 473 Mat. Res. Soc. Symp. Proc. Vol. 320. ©1994 Materials Research Society
We will call the crystallographic direction [1 120J the a axis, [1T 001 the a* axis and [0001] the c axis. The current was always parallel to the a axis and the field, for the Hall effect measurements was parallel to c. Big single crystals of NbSi2 have been obtained previously by a modified Czochralski pulling technique as described in [5]. The excellent quality of the sample was revealed by the very high residual resistance ratio of 1700, which is extremely high for a metallic compound. For the measurements of the resistivity with and without field we used the same experimental set-up as described in ref. [6]. Magnetic field was given either by a superconducting coil for fields up to 7.8 T or by the resistive magnets of the High Magnetic Field Laboratory in Grenoble for fiel
Data Loading...
