Structural and Magnetic Characterization of Co50Mn30InxSn(20-x) (x= 0, 5, 10, 15, and 20) Samples for Magnetocaloric Effect

Table of Contents

Chapter One: Magnetocaloric effect and Heusler alloy

1.1 Introduction

1.2 Thermodynamics of magnetocaloric effect

1.3 Measurements of MCE

1.4 Magnetic Refrigeration and Materilas

1.5 Magnetocaloric materials

1.6 Heusler alloy

1.7 Aim of the work

Chapter Two: Sample Preparation and Experimental Techniques

2.1 Preparation of samples

2.1.1 Arc melter

2.1.2 Melt Spinner

2.1.3 Sample Preparation

i) Master alloy

ii) Ribbon Preparation

2.2 Instrumentations

2.2.1 Preparation of system for annealing sample

2.2.2 Differential Sanning Calorimetry

2.2.3 Powder X-ray diffractometer

2.2.4 Physical Property Measurement System(PPMS)

2.2.5 Vibrating Sample Magnetometer(VSM)

Chapter Three: Results and Discussion

3.1 DSC Results

3.2 XRD Results

3.3 Magnetic Measurements

3.3.1 Hysteresis Behavior

3.3.2 Isothermal magnetization measurement

3.3.3 Thermal dependence of the magnetization measurement

3.4 MCE measurements Results

Chapter Four: General Conclusion and Future work

Research Objectives and Thematic Areas

This thesis aims to conduct a deep and systematic investigation of the magnetic and magnetocaloric properties of Co50Mn30InxSn(20-x) Heusler alloy ribbons. The primary objective is to evaluate these materials for potential applications in magnetic refrigeration technology by analyzing their structural and magnetic behaviors under various experimental conditions.

• Thermodynamics and measurement methods of the Magnetocaloric Effect (MCE).
• Synthesis and preparation techniques, including Arc Melting and Melt Spinning.
• Structural characterization using Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD).
• Magnetic property analysis via Physical Property Measurement System (PPMS) and Vibrating Sample Magnetometer (VSM).
• Evaluation of phase transitions and their impact on magnetic cooling efficiency.

Excerpt from the Thesis

Summary of Chapters

Chapter One: Magnetocaloric effect and Heusler alloy: Provides the theoretical background of the magnetocaloric effect, thermodynamics of MCE, and an overview of Heusler alloys.

Chapter Two: Sample Preparation and Experimental Techniques: Describes the methodology for synthesizing the alloy samples and the instrumentation used for characterization.

Chapter Three: Results and Discussion: Presents the findings from DSC, XRD, and magnetic measurements, analyzing phase transformations and MCE performance.

Chapter Four: General Conclusion and Future work: Summarizes the key findings of the structural and magnetic analysis and proposes directions for future research.

Keywords

Magnetocaloric effect, MCE, Heusler alloy, magnetic refrigeration, Co50Mn30InxSn(20-x), arc melting, melt spinning, thermodynamics, differential scanning calorimetry, DSC, X-ray diffraction, XRD, vibrating sample magnetometer, VSM, phase transition.

Frequently Asked Questions

What is the core focus of this research?

This work investigates the magnetic and magnetocaloric properties of Co50Mn30InxSn(20-x) alloy ribbons to determine their suitability as materials for magnetic refrigeration.

What are the central thematic fields?

The research encompasses materials science, thermodynamics of magnetic systems, experimental characterization techniques, and the development of energy-efficient refrigeration alternatives.

What is the primary goal of the thesis?

The main objective is to develop a deep and systematic study of the magnetic and magnetocaloric properties of Heusler alloy ribbons to evaluate their potential for competitive commercial refrigeration.

Which scientific methods are employed?

The study uses arc melting and melt spinning for sample preparation, followed by DSC for thermal analysis, XRD for structural investigation, and VSM/PPMS for magnetic characterization.

What topics are covered in the main body?

The main body covers the theoretical background of the magnetocaloric effect, detailed descriptions of sample synthesis, comprehensive characterization results, and the discussion of experimental data.

Which keywords characterize this work?

Key terms include Magnetocaloric effect, Heusler alloy, magnetic refrigeration, DSC, XRD, VSM, and phase transition analysis.

How does Indium content affect the magnetic properties of the samples?

The thesis finds that the Indium content influences the Curie temperature and the magnetic saturation of the samples, with certain concentrations proving more favorable for displaying high magnetocaloric effects.

What did the XRD analysis reveal about the crystalline structure?

XRD analysis confirmed the presence of the austenitic phase with L21 crystal structure in the samples, providing insight into the structural stability after heat treatment.

What impact does annealing have on the material properties?

Annealing was found to affect the grain size and phase transformation complexity, leading to different magnetic behaviors compared to the as-cast samples.