Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films

This project focuses on Ni2MnGa thin film and its aim is to obtain the five-modulated (5M) martensite. Direct Current (DC) Sputtering was applied to prepare Ni-Mn-Ga thin films on SiNx/SiO2/Si and PLZST/Pt/Ti/SiO2/Si substrates. The samples were deposited in Ar atmosphere at different sputtering pow...

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Main Author: Tan, Sofiewanty.
Other Authors: School of Materials Science and Engineering
Format: Final Year Project (FYP)
Language:English
Published: 2011
Subjects:
Online Access:http://hdl.handle.net/10356/44911
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author Tan, Sofiewanty.
author2 School of Materials Science and Engineering
author_facet School of Materials Science and Engineering
Tan, Sofiewanty.
author_sort Tan, Sofiewanty.
collection NTU
description This project focuses on Ni2MnGa thin film and its aim is to obtain the five-modulated (5M) martensite. Direct Current (DC) Sputtering was applied to prepare Ni-Mn-Ga thin films on SiNx/SiO2/Si and PLZST/Pt/Ti/SiO2/Si substrates. The samples were deposited in Ar atmosphere at different sputtering power based on different type of heat treatments used; vacuum annealing and rapid thermal process. In particular, the crystal structure and magnetic properties of the thin films were investigated as a function of sputtering and heat treatment parameters by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX) and Alternating Gradient Magnetometer (AGM). The results show that different types of heat treatments, sputtering and heat treatment parameters significantly influence the structure and magnetic properties of the thin films. When vacuum annealing was used, the films were prone to diffusion and oxidation problems. Consequently, the 5M structure was not obtained and the saturation magnetization obtained was small. For rapid thermal process, Ni-Mn-Ga thin films were found magnetic at annealing temperature of 600oC even though oxide phases still remained in the films. Fast Fourier Transform (FFT) revealed the possibility of the presence of 5M structure. It was found that higher annealing temperature and dwelling duration promote the formation of oxide phases. For sputtering power, we observed that the higher the sputtering power, the lower the magnetic properties of the films.
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spelling ntu-10356/449112023-03-04T15:36:20Z Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films Tan, Sofiewanty. School of Materials Science and Engineering Thirumany Sritharan DRNTU::Engineering::Materials This project focuses on Ni2MnGa thin film and its aim is to obtain the five-modulated (5M) martensite. Direct Current (DC) Sputtering was applied to prepare Ni-Mn-Ga thin films on SiNx/SiO2/Si and PLZST/Pt/Ti/SiO2/Si substrates. The samples were deposited in Ar atmosphere at different sputtering power based on different type of heat treatments used; vacuum annealing and rapid thermal process. In particular, the crystal structure and magnetic properties of the thin films were investigated as a function of sputtering and heat treatment parameters by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX) and Alternating Gradient Magnetometer (AGM). The results show that different types of heat treatments, sputtering and heat treatment parameters significantly influence the structure and magnetic properties of the thin films. When vacuum annealing was used, the films were prone to diffusion and oxidation problems. Consequently, the 5M structure was not obtained and the saturation magnetization obtained was small. For rapid thermal process, Ni-Mn-Ga thin films were found magnetic at annealing temperature of 600oC even though oxide phases still remained in the films. Fast Fourier Transform (FFT) revealed the possibility of the presence of 5M structure. It was found that higher annealing temperature and dwelling duration promote the formation of oxide phases. For sputtering power, we observed that the higher the sputtering power, the lower the magnetic properties of the films. Bachelor of Engineering (Materials Engineering) 2011-06-07T01:33:21Z 2011-06-07T01:33:21Z 2011 2011 Final Year Project (FYP) http://hdl.handle.net/10356/44911 en Nanyang Technological University 50 p. application/pdf
spellingShingle DRNTU::Engineering::Materials
Tan, Sofiewanty.
Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title_full Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title_fullStr Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title_full_unstemmed Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title_short Martensitic transformation in Ni2MnGa magnetic shape memory alloy thin films
title_sort martensitic transformation in ni2mnga magnetic shape memory alloy thin films
topic DRNTU::Engineering::Materials
url http://hdl.handle.net/10356/44911
work_keys_str_mv AT tansofiewanty martensitictransformationinni2mngamagneticshapememoryalloythinfilms