T. Nakama

Experimental set-up for thermopower and resistivity measurements at 100-1300 K

In this paper we describe an experimental set-up for simultaneous measurements of thermopower and electrical resistivity at temperatures from 100 K to 1300 K. Optimal configuration of electrodes and original mechanical contacts of thermocouples, current leads and potential probes with the sample make it possible to measure a large variety of materials and result in greater flexibility with respect to the sample form and dimensions. Both bulk and thin film samples with resistances in the range from 0 Ω up to 200 kΩ (1 GΩ in case of the resistivity measurement) can be investigated. Precision and high reliability of the system have been proven during more than three years of use. The resistivity and thermopower of pure Pb, Cu and Ni, and a Cr-Si thin film composite are presented as test materials to demonstrate the possibilities and accuracy of this experimental set-up.

Thermopower measurements in magnetic fields up to 17 tesla using the toggled heating method

A dc method for thermopower (TP) measurements in magnetic fields up to 17 T in the temperature range from 3 K to 300 K is introduced. A special heating technique named ‘‘seesaw heating,’’ a method similar to ac methods, was developed and resulted in good thermal stability, better accuracy and a faster procedure. Chromel–constantan thermocouples were utilized for measuring probes because of small and simple temperature dependence of magnetic field effect. Finding an empirical formula for all the calibration curves of TP of Chromel enable us to measure TP at any field and at any temperature. Finally, the experimental results on ErCo2 and LaRu2 are presented as test examples to demonstrate the possibilities and accuracy of our setup.

Anomalous magnetotransport in (Y1-xGdx)Co2alloys: Interplay of disorder and itinerant metamagnetism

New mechanism of magnetoresistivity in itinerant metamagnets with a structural disorder is introduced basing on analysis of experimental results on magnetoresistivity, susceptibility, and magnetization of structurally disordered alloys

Strongly nonlinear electronic transport in Cr-Si composite films

({mathrm{Y}}_{1ensuremath{-}x}{mathrm{Gd}}_{x}){mathrm{Co}}_{2}.

Magnetotransport in Y1-xGdxCo2 pseudobinary alloys

In this series,

Resistivity and thermopower of CaB6 single crystal

{mathrm{YCo}}_{2}

Effect of pressure on thermopower of EuNi2Ge2

is an enhanced Pauli paramagnet, whereas

Thermopower measurement under high pressure using "seesaw heating method"

{mathrm{GdCo}}_{2}

Transport properties of Cu1−xZnxIr2S4 spinel compounds

is a ferrimagnet

Contribution of spin fluctuations to the low-temperature resistivity and thermopower of YCo2

{(T}_{mathrm{c}}=400mathrm{K})