An STM works by using a sharp metallic probe tip placed very close to a sample surface. Electrons can quantum tunnel between the tip and surface. The STM maintains a constant tunneling current by precisely adjusting the tip's height as it scans the surface. This vertical movement is used to construct a topographical image of the surface with atomic resolution, revealing details of the atomic and molecular structure. STMs are powerful tools for nanoscale imaging crucial to fields like nanotechnology and materials science.

1. The Aspect Of Neutron
By Anajao,Sid Michael B.

2. 1.Neutron Basics
Start with the fundamental properties of neutrons. Neutrons are
subatomic particles found in the nucleus of an atom. They have no
electrical charge and contribute to the atomic mass. Learn about their
mass, spin, and other basic characteristics.
NUCLEUS
Neutrons
Did you know that neutron
have no electrical charge?

3. 2.Discovery of the Neutron
The history of the neutron’s discovery is fascinating. It was first
theorized by Ernest Rutherford in 1920 and later discovered by James
Chadwick in 1932. Explore the experiments and scientific
advancements that led to its identification.

4. 3.Neutron in Nuclear Physics
Neutrons are also essential in particle physics. Understanding their
interactions with other particles and their role in the structure of
atomic nuclei is a fascinating area of study.

5. 4.Neutron Stars and Beyond.
Study the role of neutrons in extreme astrophysical environments, such
as neutron stars. Neutron stars are incredibly dense and exhibit unique
properties due to the behavior of neutrons under extreme conditions.

6. 5.Nuclear Reactors and Energy Production
Explore how neutrons are used in nuclear reactors for electricity
generation. Learn about the concept of criticality, control of nuclear
reactions, and the safety aspects.

7. 6.Applications and Research
Neutrons are used in various research fields, including materials
science and biology. Neutron scattering techniques provide valuable
insights into the structure and properties of materials. Explore these
applications.

8. The formation of atomic nuclei, including the
creation of neutrons and protons

9. The formation of atomic nuclei, including the creation of neutrons and protons, occurred during the early stages of the universe
in a process known as nucleosynthesis. There are two main phases of nucleosynthesis:
1. **Primordial Nucleosynthesis:** This occurred during the first few minutes after the Big Bang. At this incredibly hot and dense
stage, only the lightest elements, such as hydrogen and helium, were formed. The universe was too hot for stable atomic nuclei
to exist, so only free protons and neutrons were present.
2. **Stellar Nucleosynthesis:** The formation of heavier elements, including stable nuclei containing protons and neutrons (such
as carbon, oxygen, iron, and beyond), occurs in the cores of stars. Stars are like nuclear reactors where nuclear fusion takes place.
High temperatures and pressures in a star’s core cause protons to combine and form helium through nuclear fusion. Later in a
star’s life, depending on its mass, heavier elements are also formed through successive fusion reactions.
Neutrons themselves are not “made” independently; they are a fundamental subatomic particle that exists in nature. They are
stable when bound within atomic nuclei but can undergo various interactions and reactions outside of nuclei.
To summarize, neutrons and protons were formed during the early moments of the universe, and they combine within atomic
nuclei during stellar nucleosynthesis, leading to the creation of all the elements we find in the universe. The detailed processes of
nucleosynthesis are studied in astrophysics and nuclear physics

10. Neutrons are one of the two types of nucleons (the other being protons) that make up the nucleus of an atom. They are
fundamental particles, meaning they are not composed of smaller particles. Neutrons are stable within the nucleus, and they are
formed during processes such as nucleosynthesis.
The formation of neutrons can occur in a few ways:
1. **Beta Decay:** Neutrons can be produced in certain types of radioactive decay, particularly in beta decay. In beta-minus
decay, a proton in the nucleus is transformed into a neutron by emitting a beta particle (an electron) and an antineutrino.
2. **Nuclear Reactions:** In nuclear reactions, such as those occurring in stars, protons can be converted into neutrons through
processes like proton-proton fusion. High temperatures and pressures in stars can facilitate these conversions.
Neutrons, once formed, are held within the nucleus by the strong nuclear force. This is one of the four fundamental forces in the
universe and is responsible for binding protons and neutrons together in the nucleus. The strong nuclear force is incredibly
powerful and acts over very short distances, effectively “gluing” the nucleons together.
The behavior of neutrons within the nucleus is governed by the laws of quantum mechanics. They do not “orbit” like electrons,
and they are subject to confinement within the nucleus due to the strong nuclear force. There isn’t an external force that keeps
them in place; it’s the inherent attraction between protons and neutrons in the nucleus that maintains their stability.

11. Scanning Tunneling Microscope (STM) 🔬

12. A Scanning Tunneling Microscope (STM) is a powerful instrument used to study surfaces at the atomic and molecular scale. It
operates based on the principles of quantum tunneling. Here’s how it works:
1. **Probe Tip:** The STM consists of a sharp metallic probe tip that is very close to the surface being studied. The probe tip is so
close that it’s almost touching the surface.
2. **Quantum Tunneling:** When the probe tip is brought very close to the surface, the electrons in the atoms of the tip and the
surface interact. Due to quantum mechanics, there’s a phenomenon known as tunneling. Electrons can “tunnel” through the small
gap between the probe tip and the surface.
3. **Feedback Mechanism:** The STM maintains a constant tunneling current by adjusting the distance between the probe tip and
the surface. As the tip scans over the surface, the height of the tip is adjusted to keep the current constant. The vertical movement
of the tip is precisely controlled, and this movement is used to create an image of the surface.
4. **Surface Imaging:** The tip moves horizontally across the surface in a systematic manner. As it follows the contours of the
surface, the height changes required to maintain a constant tunneling current are recorded. These height changes are then used to
generate a topographical map of the surface.
5. **Image Formation:** The data collected from the tip’s movement is processed to create a detailed image of the surface. The
resulting image reveals the arrangement of atoms and molecules on the surface with atomic resolution.
STMs are exceptionally powerful tools for studying nanoscale structures and have been instrumental in various scientific fields,
including nanotechnology and materials science. They can provide insights into the arrangement of atoms on surfaces and are vital
for understanding and manipulating materials at the atomic level.