Tuneable axis magnetic sensors

Ion beam materials and analysis research

We will realise a new magnetic field sensor concept, resulting in a monolithic sensor that can dynamically change the sensing direction during measurement — such a sensor is completely novel.


This sensor will overcome limitations in eddy current testing where it is necessary to measure signals which are orthogonal to a large applied field. It will also be of use in deconvolution of signals from multiple overhead conductors for fault detection. Our research will realise a wide impact for electricity networks, processing plants, pipeline infrastructure, and building integrity assessment.

Research into ion beam modification of thin films to develop novel voltage-tuneable magnetic sensors. This project is a collaboration between GNS Science and Robinson Research Institute at Victoria University of Wellington.

This programme aims to

  • develop a magnetoresistive sensor with dynamic voltage-control of the sensing axis in a plane perpendicular to the layers
  • develop the means for dynamic voltage-control of the sensing axis within the plane of the multilayers with the aim to dynamically voltage-control the sensing direction fully in three dimensions
  • integrate a sensor with this dynamic control in non-destructive testing (NDT) tools

To achieve these objectives, we will

  • modify the properties of surface materials to create magnetic sensors for non-destructive testing
  • engineer optimal magnetic anisotropy via ion irradiation

The project

Creating new magnetic sensors

This project is undertaking ion beam implantation in single and multilayer films with the aim to modify the materials properties in magnetoresistance magnetic sensors and thereby achieve voltage tuning of the sensing axis. It is part of a larger programme headed by the Robinson Research Institute (RRI) with the aim of making new magnetic sensors for non-destructive testing to ensure infrastructure reliability.

Thin films will be made at RRI and GNS Science, which are both located in Wellington, New Zealand. Implantation will be undertaken at GNS Science and ion beam methods will be used to characterise the films. The structures will be further characterised by x-ray diffraction, SEM, and TEM. The magnetic and electronic properties will be researched up to 9 T and down to 2 K using our physical property measurement system (PPMS) and our magnetic property measurement system (MPMS).

  • Publications

    Gupta, P.S.; Fiedler, H.; Rubanov, S.; Kennedy, J.V. 2021. Magnetisation and magnetic anisotropy of ion beam synthesised iron nitride. Journal of Magnetism and Magnetic Materials, 517: article 167388; doi: 10.1016/j.jmmm.2020.167388

    Mahendra, A.; Gupta, P.S.; Murmu, P.P.; Trompetter, W.J.; Kennedy, J.V. 2021. Fabrication of superparamagnetic permalloy nanostructures in ZnO matrix by ion beam sputtering. Materials Today: Proceedings, 36(2): 582-586; doi: 10.1016/j.matpr.2020.05.475

    Ahmed, S.; Cui, X.-Y.C.; Ding, X.; Murmu, P.P.; Bao, N.; Geng, X.; Xi, S.; Liu, R.; Kennedy, J.V.; Wu, T.; Wang, L.; Suzuki, K.; Ding, J.; Chu, X.; Indirathankam, S.R.C.; Peng, M.; Vinu, A.; Ringer, S.P.; Yi, J. 2020. Colossal magnetization and giant coercivity in ion-implanted (Nb and Co) MoS2 crystals. ACS Applied Materials & Interfaces, 12(52): 58140-58148; doi: 10.1021/acsami.0c18150

    Ahmed, S.; Ding, X.; Murmu, P.P.; Bao, N.; Lu, R.; Kennedy, J.V.; Wang, L.; Ding, J.; Wu, T.; Vinu, A.; Yi, J. 2020. High coercivity and magnetization in WSe2 by codoping Co and Nb. Small, 16(12): 1903173; doi: 10.1002/smll.201903173

Kennedy John 3098

John Kennedy Principal Scientist - Materials

Dr. John V Kennedy is a material scientist whose work focusses on new materials development for low carbon energy technologies. His research explores new technological pathways for a sustainable zero carbon economy. He uses ion beam technologies pioneered by Lord Rutherford to develop functional materials and to provide key information about the materials structure-property relationship. The results are used across the materials science community for the design of a new product, surface engineering, catalytic materials for hydrogen production and storage, thermoelectric materials for waste heat to energy conversion, energy storage materials, magnetic materials and energy efficient systems. John is an Adjunct Professor at Victoria University of Wellington. He is the programme director for MBIE advanced Energy technology platform “Green Hydrogen Technology Platform” which aims to develop new clean technologies to produce hydrogen from non-pure water and develop a technological capability for Hydrogen in New Zealand. He is also Energy & Emissions platform leader of New Zealand Product Accelerator and Principal Investigator of the MacDiarmid Institute for Advanced Materials and Nanotechnology and Principal Investigator of the MBIE Endeavour funded Programme “Wirelessly Powered Transport Infrastructure for a Low-carbon Future”

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Research project details

Collaborators: Victoria University of Wellington, RRI



Funding platform

MBIE Endeavour fund



Programme leader

Dr John Kennedy, GNS Science


Ministry of Business, Innovation & Employment (MBIE)

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