Najam ul Hassan, Speaker at Materials Science and Engineering Events
University of education, Pakistan
Title : Effect of Ni/Mn ratio on magneto structural coupling and magneto caloric effect in MnCoGe alloys


The magnetostructural coupling in off-stoichiometric MnCoGe alloys is realized through tuning the Mn/Co ratio, and it results in a significantentropy change (up to -30.8 J·K-1·kg-1) and wide Curie-temperature window (up to 96 K). Two scenarios have been studied, i.e., the Co-rich and Mn-rich compositions, respectively. In both scenarios, the orthorhombic-hexagonal structural transition temperature (Tt) can be shifted into the temperature range between the Curie temperatures of the orthorhombic and hexagonal phases, enabling the magnetostructural coupling between two phases. Although the magnetostructural coupling can be achieved in both scenarios, the Co-rich alloys show much higher entropy change and wider Curie-temperature window than the Mn-rich alloys. Based on the systematic structural and magnetic analyses, the composition-dependent phase diagrams for both scenarios have been constructed.
What will audience learn from your presentation?
Magnetostructural Coupling, Magnetocaloric effect, Magnetic refrigeration.
? The materials showing magnetostructural coupling) exhibit various multifunctional phenomena such as magnetocaloric effect (MCE), exchange bias (EB), magnetothermal conductivity (MC) and magnetoresistance (MR). This coupled transition is obtained around the MT temperature.
? The MCE is a magneto-thermodynamic phenomenon in which temperature is changed in the material when exposed to the external-non-constant magnetic field.
? Magnetic refrigeration is a best alternate conventional gas cooling technology, showing many, such as environment friendly, high refrigerant efficiency, low cast, occupying less space, low mechanical vibration, and harmlessness.


Dr. Hassan is working as Assistant Professor at Department of Physics, Division of Science & Technology, University of Education, Lahore, Pakistan. Before this he has worked as Assistant Professor of Physics at department of Physics, University of Central Punjab, Lahore, Pakistan. He has published more than 25 research papers in well-known International journals of Physics & Materials Science. He has also served as committee member, reviewer and keynote speaker in various International Conferences/Symposiums.
Dr. Hassan did his Ph.D. in Materials Science & Engineering from Nanjing University of Science & Technology, Nanjing, China. Before commencing his doctoral degree, he has worked as subject specialist in Higher Education Department, Punjab Province, Pakistan.