Publications by Simon Granville

Large Anomalous Nernst Angle in Co2MnGa Thin Film

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Song Liu, Junfeng Hu, Yao Zhang

The new trends for anomalous Nernst effect (ANE)-based thermoelectric devices require materials with large ANE values to realize the scalable generation of voltage. Recently, very large ANE values have been observed in single crystals of some novel magneti ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Regulating the anomalous Hall and Nernst effects in Heusler-based trilayers

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Song Liu, Sa Tu, Junfeng Hu

Anomalous Hall and anomalous Nernst properties of thin MgO/Co-2Fe0.4Mn0.6Si/Pd stacks with perpendicular magnetic anisotropy (PMA) revealed the presence of the magnetic proximity effect (MPE) in the Pd layer. The MPE is evidenced by nanometer range thickne ...

2020

Anomalous Nernst effect in Co2MnGa thin films with perpendicular magnetic anisotropy

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Song Liu, Sa Tu, Junfeng Hu, Yao Zhang

The thermoelectric and transport properties of MgO/Co2MnGa/Pd stacks with perpendicular magnetic anisotropy were measured. For a nominal 3.3 nm Co2MnGa thickness, the anomalous Nernst coefficient and the Nernst angle at room temperature were found to be 0. ...

ELSEVIER2020

Spin-Dependent Thermoelectric Transport in Cobalt-Based Heusler Alloys

Simon Granville, Haiming Yu, Junfeng Hu

Sitting at the intersection of spintronics and thermoelectricity, research investigating the coupling of thermoelectric, magnetic, and electrical transport properties in materials has recently found that the ferromagnetic Heusler alloys are the ideal testb ...

WILEY-V C H VERLAG GMBH2020

Cu codoping control over magnetic precipitate formation in ZnCoO nanowires

Simon Granville

Using electrodeposition, we have grown nanowires of ZnCoO with Cu codoping concentrations varying from 4-10 at. %, controlled only by the deposition potential. We demonstrate control over magnetic Co oxide nano-precipitate formation in the nanowires via th ...

Amer Inst Physics2014

Low-temperature hopping and absence of spin-dependent transport in single crystals of cobalt-doped ZnO

Jean-Philippe Ansermet, Simon Granville

Long needle-shaped single crystals of Zn1-xCoxO were grown at low temperatures using a molten salt solvent technique, up to x=0.10. The conduction process at low temperatures is determined to be Mott variable range hopping. Both pristine and cobalt-doped c ...

2010

Nearest-neighbor Mn antiferromagnetic exchange in Ga(1-x)MnxN

Harry Joseph Trodahl, Simon Granville

We analyze the magnetic behavior of well-characterized, precipitate-free Ga1-xMnxN thin films containing Mn at higher levels than previously attained; up to x=0.36. This level is above the percolation threshold x(c) for nearest-neighbor cations, such that ...

2010

Second Harmonic Detection of Spin-Dependent Transport in Magnetic Nanostructures

Jean-Philippe Ansermet, Simon Granville

Detection of the second harmonic response of magnetic nanostructures to an ac current is shown to be a very sensitive probe of the magnetization reversal process. A temperature oscillation is obtained by Joule heating instead of using a laser as the heat s ...

2010

Temperature derivative of the resistance of spin valves

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Julie Dubois

Spin-dependent transport properties of nanowires containing individual Co/Cu/Co pseudo-spin valves were investigated by monitoring an AC voltage induced by a temperature oscillation under a continuous DC current. We observed sharp peaks in the field-depend ...

Elsevier2010

Electrodeposition and Characterization of Bismuth Telluride Nanowires

Simon Granville

In this work, we report thermoelectric measurements on electroplated bismuth telluride nanowires. Porous polycarbonate membranes, obtained by ion-track irradiation lithography, were chosen as electroplating templates. Bismuth telluride nanowires were achie ...

2010

Heat and spin transport in magnetic nanowires

Jean-Philippe Ansermet, Simon Granville, Haiming Yu

Transport measurements are carried out in which temperature oscillation is applied to magnetic nanostructures. Using spin valves, this measurement reveals aspects of the spin transport in non-collinear configurations. In one implementation, an AC voltage i ...

Elsevier2010

Evidence for Thermal Spin-Transfer Torque

Jean-Philippe Ansermet, Simon Granville, Haiming Yu

Large heat currents are obtained in Co/Cu/Co spin valves positioned at the middle of Cu nanowires. The second harmonic voltage response to an applied current is used to investigate the effect of the heat current on the switching of the spin valves. Both th ...

American Physical Society2010

Vibrational properties of rare-earth nitrides: Raman spectra and theory

Harry Joseph Trodahl, Simon Granville

Raman spectra are presented for the rare-earth nitrides SmN, GdN, DyN, ErN, and LuN measured with 633 and 514 nm excitation wavelengths and at temperatures above and below the Curie temperature. Frozen-phonon calculations are presented for the phonons at G ...

2009

Current susceptibility of magnetization in spin valves

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Julie Dubois

We observed the second harmonic voltage response of pseudo-spin valves subjected to currents oscillating at frequencies in the sub-kilohertz range. Peaks appear in its magnetic field dependence, with a signal-to-noise ratio equal to or greater than the mag ...

2009

Near-zero-moment ferromagnetism in the semiconductor SmN

Harry Joseph Trodahl, Simon Granville

The magnetic behavior of SmN has been investigated in stoichiometric polycrystalline films. All samples show ferromagnetic order with Curie temperature (T-C) of 27 3 K, evidenced by the occurrence of hysteresis below T-C. The ferromagnetic state is charact ...

2008

Charge trapping effects in photovoltage measurements of (Ga,Mn)As

Jean-Philippe Ansermet, Simon Granville

We report charge trapping effects in a ferromagnetic (Ga,Mn)As thin film observed during measurements of the photovoltage under inhomogeneous illumination conditions. Using a laser diode as the excitation source, the temperature-dependent response has been ...

2008

Preparation and Properties of Cobalt Doped ZnO Nanowires

Jean-Philippe Ansermet, Simon Granville

The template method was used for preparing Zn1-xCoxO nanowires with x ranging from 0.01 to 0.05. Thus, electrochemical deposition was employed for filling up the pores of polycarbonate ion track nanoporous membranes with the desired material. The method al ...

Institute of Electrical and Electronics Engineers2008