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Strategy to Develop the High-Performance Thermomagnetic Gd-Si-Ge Alloys for Low-grade Waste Heat Energy Harvesting

ORAL

Abstract

Searching for new technology for energy harvesting from low-grade waste heat via the use of magnetic phase change materials is one of the focused research areas within the domain of renewable energy resources. The key challenges to be addressed simultaneously are (i) a large change in magnetization with temperature, (ii) magnetic phase transition at/near room temperature, and (iii) high thermal conductivity. In this work, we established SeS2 as an extraordinary sintering aid that effectively densifies the high-performing Gd5Si2.4Ge1.6 thermomagnetic material via low-temperature spark plasma sintering at 200 °C. The weight ratio of SeS2 per unit gram is optimized to improve the density by 32%, thermal conductivity by 90%, and maintained the large magnetization in the Gd5Si2.4Ge1.6 compound. The magnetic phase transition of 33 °C is successfully achieved for (Gd5Si2.4Ge1.6)0.9(SeS2)0.1 material.

In order to further improvement in the magnetic and thermal properties of Gd5Si2.4Ge1.6 compound, a constructive screening of the best composition with doping at Gd site is desirable. In this direction the thermomagnetic properties are estimated by partially filled 3d, 4d, and 4f elements from transition metal and rare-earth elements by using the first principle modeling based tools implemented in KKR-CPA and VASP codes. Computational results show that by co-doping of V and Co element at Gd site the magnetic properties improves by 56 % as compared to un-doped Gd5Si2.4Ge1.6 compound.

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Presenters

  • saurabh Singh

    Penn State University Park PA USA

Authors

  • saurabh Singh

    Penn State University Park PA USA

  • Na Liu

    Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA.

  • Amin Nozariasbmarz

    Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA.

  • Bed Poudel

    Department of Materials Science and Engineering, Pennsylvania State University, Penn State University, The Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA.

  • Shashank Priya

    Department of Materials Science and Engineering, Pennsylvania State University, Penn State University, Penn State, The Pennsylvania University, Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA.