Properties of Crystals PDF

RIZAL TECHNOLOGICAL UNIVERSITY Cities of Mandaluyong and Pasig MODULE 4 – PROPERTIES OF CRYSTALS Materials around us are composed of elements and their combinations. Some of the materials are solid...

RIZAL TECHNOLOGICAL UNIVERSITY Cities of Mandaluyong and Pasig MODULE 4 – PROPERTIES OF CRYSTALS Materials around us are composed of elements and their combinations. Some of the materials are solid like metals, plastics, glasses, and crystals. The latter is commonly used as decorations and accessories during events. Crystals have different colors, structure, and formation. Most of the time, unique, colorful, and attractive crystals are expensive than those common one. In this lesson, the science of crystal is discussed. Crystals are solids materials having a regularly repeating arrangement of atoms. Any crystal may be regarded as being built up by the continuing three-dimensional translational repetition of some basic structural pattern. Crystal is any solid that has an organized structure. That means that the atoms of this thing are positioned in very accurate distances and angles one from the other, as opposed to glass for example, in which atoms are in a more or less random arrangement. Crystallography is the science that examines crystals, which can be found everywhere in nature, from salt to snowflakes to gemstones. This Upper Picture: Calcite Mineral. Lower Picture: Microscopic Image of science study the crystalline of materials, their structure and properties. Calcite. (Custodio, M.) Crystallographers use the properties and inner structures of crystals to determine the arrangement of atoms and generate knowledge that is used by chemists, physicists, biologists, and others disciplines. Crystal Structure A crystal structure is composed of unit cell, a set of atoms arranged in a particular way, which is periodically repeated in three dimensions on a lattice. Many properties of materials depend on their crystal structures. The X- ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) are some of the characterization techniques are used to the science of materials.  Example of data gathered using XRD. Sample is Bi-2223 Powder (Superconductor). Custodio, et. al. - Crystal Structure may be broken down into alattice and a bases. - 2 Dimensions and 3 Dimensions Example of STMimage of Graphene material.Kim, J. et. al The atoms can be arranged with and without forms. Crystalline are solids in which the constitute particles of matter are arranged and organized in a specific manner. These solids contain crystals in their structure and each crystal has definite geometry. The have well defined shapes because their particles— atoms, molecules, or ions—occur in an orderly arrangement consist of particles tightly packed into a regular array called a lattice.  The lattice of a solid is the two or three-dimensional arrangement of points created by choosing each point to be at the same location within each particle of a crystal; thus, the lattice consists of all points with identical surroundings. On the other hand, the non-crystalline or amorphous and the solids in which the constituent particles of matter are arranged in a random manner. It is a non-crystalline solid with no proper arrangement of atoms in the solid lattice. They have poorly defined shapes because their particles lack an orderly arrangement throughout the sample. Example of amorphous solid are rubbers, glasses, and obsidians (volcanic glasses). Amorphous solids with irregular arrangement of atoms in patches also breaks unevenly whenever force is applied or is broken. These solids do not break in any regular pattern as is evident in crystals but rather break at random as the weakest bond at places is not evenly placed within the amorphous solid structure.  REFERENCE Book: Disclaimer: This Module is an excerpt from the work of Custodio, Margareth (2018) and. Module on Properties of Crystal and from Jose, Emalyn (2020) Crystal Structure. College of Engineering, Architecture, and Technology. Images taken from Google Image