Measuring Changes in Surface Magnetism Using the Planar Hall Effect

Author(s)

Nghia NguyenFollow

School Name

South Carolina Governor's School for Science & Mathematics

Grade Level

12th Grade

Presentation Topic

Physics

Presentation Type

Mentored

Abstract

Prior research has shown that the application of solvents can change the magnetic properties of thin film metals. For example, solvents can reduce the coercivity of thin film metals and change gold from a diamagnetic to a paramagnetic metal. However, this effect is not yet understood. My research focused on the use of Hall bars to measure these changes in surface magnetism. Our research group at the University of South Carolina wanted to study this phenomenon, so we used the planar Hall effect to observe coercivity in thin film metals. Hall bars are created using photolithography and thermal evaporated metal in the presence of a magnetic field. These Hall bars use the planar Hall effect (PHE) to produce two voltage peaks in an externally applied, alternating magnetic field. The separation of the two PHE peaks are dependent on the coercivity of the metal. The objective is to collect data on magnetic field and Hall voltage and compare it to the data after application of solvents. A change in coercivity would therefore indicate changes in the in-plane magnetic field. However, only preliminary data was taken. Therefore, no decisive conclusions can be made. If successful, this research can expand our knowledge of magnetic properties of metals and be controlled for applications in computer engineering, such as computer memory and logic gates.

Location

Founders Hall 210 B

Start Date

3-30-2019 11:00 AM

Presentation Format

Oral Only

Group Project

No

COinS
 
Mar 30th, 11:00 AM

Measuring Changes in Surface Magnetism Using the Planar Hall Effect

Founders Hall 210 B

Prior research has shown that the application of solvents can change the magnetic properties of thin film metals. For example, solvents can reduce the coercivity of thin film metals and change gold from a diamagnetic to a paramagnetic metal. However, this effect is not yet understood. My research focused on the use of Hall bars to measure these changes in surface magnetism. Our research group at the University of South Carolina wanted to study this phenomenon, so we used the planar Hall effect to observe coercivity in thin film metals. Hall bars are created using photolithography and thermal evaporated metal in the presence of a magnetic field. These Hall bars use the planar Hall effect (PHE) to produce two voltage peaks in an externally applied, alternating magnetic field. The separation of the two PHE peaks are dependent on the coercivity of the metal. The objective is to collect data on magnetic field and Hall voltage and compare it to the data after application of solvents. A change in coercivity would therefore indicate changes in the in-plane magnetic field. However, only preliminary data was taken. Therefore, no decisive conclusions can be made. If successful, this research can expand our knowledge of magnetic properties of metals and be controlled for applications in computer engineering, such as computer memory and logic gates.