Slide 1

• Topic: Diamagnetic, Paramagnetic And Ferromagnetic Materials
• Introduction to Magnetism
• Definition of Diamagnetic materials
• Examples of Diamagnetic materials: copper, gold
• Explanation of the behavior of Diamagnetic materials in a magnetic field

Slide 2

• Definition of Paramagnetic materials
• Explanation of the behavior of Paramagnetic materials in a magnetic field
• Examples of Paramagnetic materials: aluminum, platinum
• Comparison between Diamagnetic and Paramagnetic materials
• Magnetic susceptibility and its relation to Paramagnetic materials

Slide 3

• Introduction to Ferromagnetic materials
• Explanation of the behavior of Ferromagnetic materials in a magnetic field
• Examples of Ferromagnetic materials: iron, nickel
• Permanent magnetism and its relation to Ferromagnetic materials
• Explanation of domains in Ferromagnetic materials

Slide 4

• Formation and alignment of domains in Ferromagnetic materials
• Hysteresis loop and its significance in Ferromagnetic materials
• Magnetic susceptibility and its relation to Ferromagnetic materials
• Ferromagnetic materials used in practical applications: magnets, transformers
• Magnetic field lines around Ferromagnetic materials

Slide 5

• Magnetic Field Of The Earth
• Definition of Earth’s magnetic field
• Explanation of the concept of magnetic poles
• Earth’s magnetic field lines and their direction
• Importance of Earth’s magnetic field in navigation and compasses

Slide 6

• Effect of Earth’s magnetic field on a compass needle
• Explanation of declination and inclination
• Magnetic equator and magnetic poles
• Magnetic field strength and variations across the Earth’s surface
• Measurement of Earth’s magnetic field using a magnetometer

Slide 7

• Diamagnetic Materials
  • Definition and properties of Diamagnetic materials
  • Diamagnetic substances repelled by a magnetic field
  • Examples: Copper, Gold, Silver
• Paramagnetic Materials
  • Definition and properties of Paramagnetic materials
  • Paramagnetic substances weakly attracted to a magnetic field
  • Examples: Aluminum, Platinum, Titanium

Slide 8

• Ferromagnetic Materials
  • Definition and properties of Ferromagnetic materials
  • Ferromagnetic substances strongly attracted to a magnetic field
  • Examples: Iron, Nickel, Cobalt
• Relationship between magnetic properties and electronic configuration
• Magnetic moments of atoms and its role in magnetism

Slide 9

• Magnetic domains in Ferromagnetic materials
  • Definition and explanation of magnetic domains
  • Alignment of magnetic moments within domains
  • Domain walls and their significance
• Hysteresis loop in Ferromagnetic materials
  • Definition and explanation of hysteresis loop
  • Magnetic field strength vs magnetization curve

Slide 10

• Uses of Ferromagnetic materials in everyday life
  • Transformers and their operation
  • Magnetic storage devices: hard drives, magnetic tapes
  • Electromagnets and their applications
• Summary and key points
• Importance of understanding magnetic materials in physics studies
• Questions and answers session

Slide 11

• Properties of Diamagnetic materials:
  • When placed in a magnetic field, they create an induced magnetic field in the opposite direction.
  • They have a negative magnetic susceptibility.
  • They are weakly repelled by a magnetic field.
  • The magnetic moment of atoms in Diamagnetic materials is zero.

Slide 12

• Diamagnetic substances have all electrons paired.
• The application of an external magnetic field causes a rearrangement of electrons.
• Examples of Diamagnetic materials:
  • Copper: Cu has a completely filled d-orbital, making it Diamagnetic.
  • Gold: Au has all its valence electrons paired, resulting in Diamagnetic behavior.

Slide 13

• Properties of Paramagnetic materials:
  • When placed in a magnetic field, they create an induced magnetic field in the same direction.
  • They have a positive magnetic susceptibility.
  • They are weakly attracted to a magnetic field.
  • The magnetic moment of atoms in Paramagnetic materials is non-zero.

Slide 14

• Paramagnetic substances have unpaired electrons.
• The application of an external magnetic field aligns the spins of unpaired electrons.
• Examples of Paramagnetic materials:
  • Aluminum: Al has three unpaired electrons in its orbital, resulting in Paramagnetic behavior.
  • Platinum: Pt has two unpaired electrons, making it Paramagnetic.

Slide 15

• Properties of Ferromagnetic materials:
  • When placed in a magnetic field, they create a strong induced magnetic field of their own.
  • They have a high positive magnetic susceptibility.
  • They are strongly attracted to a magnetic field.
  • The magnetic moment of atoms in Ferromagnetic materials is high and aligned.

Slide 16

• Ferromagnetic substances have unpaired electrons and spontaneous alignment of their spins.
• The alignment causes a net magnetic moment at each atom and domains within the material.
• Examples of Ferromagnetic materials:
  • Iron: Fe has multiple unpaired electrons and a high magnetic moment, exhibiting strong Ferromagnetic behavior.
  • Nickel: Ni also has unpaired electrons and a high magnetic moment, making it Ferromagnetic.

Slide 17

• Magnetic field of the Earth is generated by the motion of molten iron in its outer core.
• The Earth’s magnetic field is approximately equivalent to that of a bar magnet.
• It extends from the Earth’s interior towards the geographical North Pole and emerges at the South Pole.
• The direction of the magnetic field at any point can be represented by magnetic field lines.

Slide 18

• A compass needle aligns itself with the magnetic field lines of the Earth.
• The needle points towards the Earth’s magnetic North Pole, which is close to the geographical South Pole.
• The angle between the magnetic north and true north is called declination.
• Inclination refers to the angle the magnetic field lines make with the Earth’s horizontal plane.

Slide 19

• The strength of the Earth’s magnetic field is not uniform across the globe.
• The highest and lowest intensities indicate magnetic poles and an equator called the magnetic equator.
• The magnetic field strength varies due to the presence of magnetic anomalies in different regions of the Earth.
• A magnetometer is used to measure the Earth’s magnetic field strength and its variations.

Slide 20

• Summary of the lecture:
  • Diamagnetic materials are weakly repelled by a magnetic field.
  • Paramagnetic materials are weakly attracted to a magnetic field.
  • Ferromagnetic materials are strongly attracted to a magnetic field and exhibit permanent magnetism.
  • The Earth’s magnetic field affects compass needles, and its measurement helps in navigation.
• Conclusion and Q&A.

Slide 21

• Diamagnetic Materials (continuation)
  • Diamagnetic materials have a negative magnetic susceptibility.
  • They exhibit weak repulsion when placed in a magnetic field.
  • The magnitude of the induced magnetic moment opposes the applied magnetic field.
  • Diamagnetic materials have a relative permeability slightly less than 1.
  • The behavior of Diamagnetic materials is explained by Lenz’s law.

Slide 22

• Paramagnetic Materials (continuation)
  • Paramagnetic materials have a positive magnetic susceptibility.
  • They exhibit weak attraction when placed in a magnetic field.
  • The magnitude of the induced magnetic moment aligns with the applied magnetic field.
  • Paramagnetic materials have a relative permeability slightly greater than 1.
  • The behavior of Paramagnetic materials is explained by Langevin’s theory.

Slide 23

• Ferromagnetic Materials (continuation)
  • Ferromagnetic materials have a high positive magnetic susceptibility.
  • They exhibit strong attraction when placed in a magnetic field.
  • The magnitude of the induced magnetic moment is significantly higher than the applied magnetic field.
  • Ferromagnetic materials have a relative permeability much greater than 1.
  • The behavior of Ferromagnetic materials is explained by exchange interactions between neighboring atoms.

Slide 24

• Domains in Ferromagnetic Materials (continuation)
  • Ferromagnetic materials have multiple domains composed of aligned magnetic moments.
  • Each domain acts like a tiny magnet with its own north and south poles.
  • The number and size of domains determine the overall magnetic behavior of the material.
  • Domain walls are boundaries between neighboring domains.
  • The alignment of domains can be influenced by external magnetic fields and temperature changes.

Slide 25

• Hysteresis Loop in Ferromagnetic Materials (continuation)
  • The hysteresis loop describes the relationship between magnetization and magnetic field strength.
  • It shows how magnetization changes as the external magnetic field is increased and then decreased.
  • The loop has two branches: the increasing field or magnetizing branch and the decreasing field or demagnetizing branch.
  • The area enclosed by the hysteresis loop represents energy loss due to magnetic hysteresis.
  • Hysteresis is an important property in applications like magnetic data storage and transformers.

Slide 26

• Earth’s Magnetic Field (continuation)
  • The Earth’s magnetic field is essential for the existence of life on our planet.
  • It protects us from harmful solar radiation by deflecting charged particles.
  • It enables animals like birds and sea turtles to navigate during migration.
  • The strength of the Earth’s magnetic field is measured in teslas (T) or gauss (G).
  • The Earth’s magnetic field varies across its surface due to its internal dynamics.

Slide 27

• Effect of Earth’s Magnetic Field on a Compass Needle (continuation)
  • A compass needle aligns itself with the Earth’s magnetic field lines.
  • The magnetic field causes the needle to point towards the magnetic North Pole.
  • The angle between the magnetic North Pole and the true North Pole is called declination.
  • In certain regions, the magnetic field lines point vertically downwards, resulting in zero inclination.
  • The behavior of compass needles is influenced by nearby ferromagnetic materials and electric currents.

Slide 28

• Magnetic Equator and Magnetic Poles (continuation)
  • The equator where the Earth’s magnetic field is horizontal is known as the magnetic equator.
  • The magnetic poles are locations where the magnetic field lines enter or emerge from the Earth’s surface vertically.
  • The magnetic North Pole is located near the geographical South Pole.
  • The magnetic South Pole is located near the geographical North Pole.
  • The strength of the magnetic field is maximum near the magnetic poles.

Slide 29

• Magnetic Field Intensity across the Earth’s Surface (continuation)
  • The Earth’s magnetic field is not uniform across its surface.
  • Magnetic anomalies are irregularities in the Earth’s magnetic field caused by variations in the composition and structure of rocks.
  • Positive anomalies indicate regions with a higher magnetic field strength, while negative anomalies represent regions with a lower magnetic field strength.
  • Magnetic surveys are conducted to map the Earth’s magnetic field and identify anomalies.
  • Understanding these variations helps in various fields, including geology, archaeology, and resource exploration.

Slide 30

• Summary and Conclusion
  • Diamagnetic, Paramagnetic, and Ferromagnetic materials exhibit different behaviors when placed in a magnetic field.
  • The Earth’s magnetic field plays a crucial role in navigation, protection from radiation, and wildlife migration.
  • Understanding magnetic materials and the Earth’s magnetic field is vital in various scientific and technological applications.
  • The study of magnetism opens up opportunities to explore the fundamental properties of matter and the interactions between magnetic fields and materials.
• Questions and Answers.