Condensed Matter Physics

Study Notes

Condensed Matter Physics

Studies the macroscopic and microscopic physical properties of matter, involving a large number of interacting constituents (atoms or molecules).
Deals with properties of matter at ordinary chemical and thermal energy scales.
Has the largest number of direct practical applications and is intellectually vital.

Crystals

Solid materials with a highly ordered, repeating pattern called a crystal lattice.
Characteristic shape and structure are due to this orderly arrangement.
Types of bonding:
- Ionic Bonding: occurs when electrons are transferred from one atom to another, resulting in positively charged ions (cations) and negatively charged ions (anions).
Bragg's Law: describes the diffraction of x-rays by crystals, relating to the wavelength of the incident x-ray, distance between crystal planes, and angle of incidence.

Semiconductors

The Current-Voltage Relationship for a Diode (Shockley Diode Equation) models the exponential relationship between the diode current and voltage across the diode.
Equation: 𝐼 = 𝐼0 (𝑒 𝑛𝑉𝑇 – 1)
Where: I is the diode current, I0 is the reverse saturation current, V is the voltage across the diode terminals, n is the ideality factor, and VT is the thermal voltage.

History of Condensed Matter

Humphry Davy (Early 19th Century): challenged John Dalton's atomic theory, observing metallic properties in chemical elements, and suggested that atoms had inner structures.
Michael Faraday (1823): successfully liquefied gases, including chlorine, expanding our understanding of the behavior of matter under extreme conditions.

Laboratory Activity: Investigating Thermal Conductivity in Condensed Matter

Objective: to explore the thermal conductivity of various condensed matter materials and understand its implications in practical applications.
Materials needed: metal spoon, ceramic mug, plastic container, heat source, stopwatch or timer, thermometer, and ruler.
Procedure:
- Measure dimensions of each material and record initial temperatures.
- Heat one end of each material uniformly using a heat source.
- Record time taken for temperature to increase by a predetermined amount (ΔT) at 20°C.
- Repeat the experiment for each material to ensure reliability and precision.
- Calculate the rate of temperature increase and compare thermal conductivities of different materials based on calculated rates.

Description

This quiz covers the study of macroscopic and microscopic physical properties of matter, including systems involving a large number of particles. It is a fundamental topic in physics, particularly for engineers.