Orientation (geometry)

Isotropic solid

In condensed matter physics and continuum mechanics, an isotropic solid refers to a solid material for which physical properties are independent of the orientation of the system. While the finite sizes of atoms and bonding considerations ensure that true isotropy of atomic position will not exist in the solid state, it is possible for measurements of a given property to yield isotropic results, either due to the symmetries present within a crystal system, or due to the effects of orientational averaging over a sample (e.g. in an amorphous solid or a polycrystalline metal). Isotropic solids tend to be of interest when developing models for physical behavior of materials, as they tend to allow for dramatic simplifications of theory; for example, conductivity in metals of the cubic crystal system can be described with single scalar value, rather than a tensor. Additionally, cubic crystals are isotropic with respect to thermal expansion and will expand equally in all directions when heated. Isotropy should not be confused with homogeneity, which characterizes a system’s properties as being independent of position, rather than orientation. Additionally, all crystal structures, including the cubic crystal system, are anisotropic with respect to certain properties, and isotropic to others (such as density). The anisotropy of a crystal’s properties depends on the rank of the tensor used to describe the property, as well as the symmetries present within the crystal. The rotational symmetries within cubic crystals, for example, ensure that the dielectric constant (a 2nd rank tensor property) will be equal in all directions, whereas the symmetries in hexagonal systems dictate that the measurement will vary depending on whether the measurement is made within the basal plane. Due to the relationship between the dielectric constant and the optical index of refraction, it would be expected for cubic crystals to be optically isotropic, and hexagonal crystals to be optically anisotropic; Measurements of the optical properties of cubic and hexagonal CdSe confirm this understanding. Nearly all single crystal systems are anisotropic with respect to mechanical properties, with Tungsten being a very notable exception, as it is a cubic metal with stiffness tensor coefficients that exist in the proper ratio to allow for mechanical isotropy. In general, however, cubic crystals are not mechanically isotropic. However, many materials, such as structural steel, tend to be encountered and utilized in a polycrystalline state. Due to random orientation of the grains within the material, measured mechanical properties tend to be averages of the values associated with different crystallographic directions, with the net effect of apparent isotropy. As a result, it is typical for parameters such as the Young's Modulus to be reported independent of crystallographic direction. Treating solids as mechanically isotropic greatly simplifies analysis of deformation and fracture (as well as of the elastic fields produced by dislocations ). However, preferential orientation of grains (called texture) can occur as a result of certain types of deformation and recrystallization processes, which will create anisotropy in mechanical properties of the solid. (Wikipedia).

Video thumbnail

Organic Chemistry - Ch 1: Basic Concepts (19 of 97) What is an Optical Isomer?

Visit http://ilectureonline.com for more math and science lectures! In this video I will explain what is an optical isomer: a mirror image of another. There are 2 types. Achiral-when the 2 are superimposable, and chiral-molecules that exhibit handedness. Next video in this series can be

From playlist ORGANIC CHEMISTRY CH1 INTRODUCTION

Video thumbnail

Isopropyl Chloride Synthesis: Making an Alkyl Halide | DIY Gasoline (Part 1)

Isopropyl chloride is a clear, volatile liquid with an extremely low boiling point (only 36 degrees Celsius). It belongs to a family of chemicals known as alkyl halides, which have a variety of uses in organic chemistry, such as in the Williamson ether synthesis or the Grignard reaction. I

From playlist Chemical madness

Video thumbnail

Isopropyl nitrite (an antidote, outdated medicine and chemical with white fire)

In this video we are making isopropyl nitrite which burns with a white flame. It was once used as an antidote for cyanide poisoning and as a medicine for high blood pressure but has been teken off the market due to too many adverse effects. Instagram: https://www.instagram.com/thyzoyd/?hl

From playlist Organic Chemistry

Video thumbnail

Crystalline vs Amorphous materials

Materials are either crystalline or amorphous. They contain long-range periodic order or they do not. This leads to very different properties! Crystalline materials can be either polycrystalline or single crystal in nature. we can see evidence of single crystals in faceting of crystal face

From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020

Video thumbnail

Isomers- Stereoisomers

Watch more videos on http://www.brightstorm.com/science/chemistry SUBSCRIBE FOR All OUR VIDEOS! https://www.youtube.com/subscription_center?add_user=brightstorm2 VISIT BRIGHTSTORM.com FOR TONS OF VIDEO TUTORIALS AND OTHER FEATURES! http://www.brightstorm.com/ LET'S CONNECT! Facebook ► h

From playlist Chemistry

Video thumbnail

Binary phase diagrams

When two components are mixed, we need to do a binary phase diagram. The simplest of these is a isomorphous binary phase diagram. One example is the Ni-Cu system. In this system, we see a solidus line, liquidus line, and complete solutions in the liquid and solid phases.

From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020

Video thumbnail

HL Stereochemistry

IB HL Chemistry lesson on stereoisomerism

From playlist IB Chemistry

Video thumbnail

Physics - Thermodynamics: (11 of 22) Change Of State: Constant Volume (Isovolumetric) Isochoric

Visit http://ilectureonline.com for more math and science lectures! In this video I will show you how to calculate the pressures, work done by and heat added to the gas of an isovolumetric process.

From playlist PHYSICS - THERMODYNAMICS

Video thumbnail

Physics - Thermodynamics: (7 of 22) Change Of State: Constant Pressure (Isobaric) Ex. 1

Visit http://ilectureonline.com for more math and science lectures! In this video I will give an example of an isobaric (constant) process.

From playlist PHYSICS - THERMODYNAMICS

Video thumbnail

Ingrid Membrillo Solis (2/24/21): Liquid crystals dynamics: what persistent homology reveals

Title: The dynamics of the phase transition in liquid crystals: what persistent homology reveals Abstract: Liquid crystals are a state of matter that present physical properties interpolating between those of conventional liquids and those of crystals. The phase dynamics of liquid crystal

From playlist AATRN 2021

Video thumbnail

7. Natural Honeycombs: Cork; Foams: Linear Elasticity

MIT 3.054 Cellular Solids: Structure, Properties and Applications, Spring 2015 View the complete course: http://ocw.mit.edu/3-054S15 Instructor: Lorna Gibson This session begins with a look at cork as a natural honeycomb structure, and covers properties of foams and some modeling. Licens

From playlist MIT 3.054 Cellular Solids: Structure, Properties and Applications, Spring 2015

Video thumbnail

Amorphous solids: Failure via Cavitation by Pinaki Chaudhuri

DISCUSSION MEETING 8TH INDIAN STATISTICAL PHYSICS COMMUNITY MEETING ORGANIZERS: Ranjini Bandyopadhyay (RRI, India), Abhishek Dhar (ICTS-TIFR, India), Kavita Jain (JNCASR, India), Rahul Pandit (IISc, India), Samriddhi Sankar Ray (ICTS-TIFR, India), Sanjib Sabhapandit (RRI, India) and Prer

From playlist 8th Indian Statistical Physics Community Meeting-ispcm 2023

Video thumbnail

Elastic constant interrelations (Shear modulus, Poisson's ratio, Young's modulus) example problem

Tutorial worked example problem of how to convert from a stress and changes in length to Elastic modulus to Poisson's ratio to Shear modulus and eventually to a shear stress. *subscribe to help me grow this channel and comment below with a suggested new mse problem to solve*

From playlist MSE example problems tutorial

Video thumbnail

Molecular Structure & Statistical Mechanics 131B. Lecture 17. NMR (Pt. II)

UCI Chem 131B Molecular Structure & Statistical Mechanics (Winter 2013) Lec 17. Molecular Structure & Statistical Mechanics -- NMR -- Part 2. View the complete course: http://ocw.uci.edu/courses/chem_131b_molecular_structure_and_elementary_statistical_mechanics.html Instructor: Rachel Mart

From playlist Chem 131B: Molecular Structure & Statistical Mechanics

Video thumbnail

Janus Clusters - from Birth to Death by Steve Granick

Conference and School on Nucleation Aggregation and Growth URL: https://www.icts.res.in/program/NAG2010 DATES: Monday 26 July, 2010 - Friday 06 Aug, 2010 VENUE : Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru DESCRIPTION: Venue: Jawaharlal Nehru Centre for Advance

From playlist Conference and School on Nucleation Aggregation and Growth

Video thumbnail

Criticality and Marginal Stability of Frictionless Shear jammed Spheres by Varghese Babu

DISCUSSION MEETING APS SATELLITE MEETING AT ICTS ORGANIZERS Ranjini Bandyopadhyay (RRI, India), Subhro Bhattacharjee (ICTS-TIFR, India), Arindam Ghosh (IISc, India), Shobhana Narasimhan (JNCASR, India) and Sumantra Sarkar (IISc, India) DATE & TIME: 15 March 2022 to 18 March 2022 VENUE:

From playlist APS Satellite Meeting at ICTS-2022

Video thumbnail

Solid State Physics in a Nutshell: Topic 6-2: Heat Capacity with the Debye Model

We discuss the Debye model which invokes a linear, isotropic dispersion and uses that to solve for the heat capacity of a solid.

From playlist CSM: Solid State Physics in a Nutshell | CosmoLearning.org Physics

Video thumbnail

Poisson's ratio

When you strain a material along one axis, you often see corresponding strain perpendicular to the load direction. A material under tension gets thinner, for example. The ratio of these two strains is defined as Poisson's ratio. Most materials are between 0.25-0.35 with some exceptions. Is

From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020

Video thumbnail

Canonical Forms in Geometry and Soliton Theory - Chuu-Lian Terng

Glimpses of Mathematics, Now and Then: A Celebration of Karen Uhlenbeck's 80th Birthday Topic: Canonical Forms in Geometry and Soliton Theory Speaker: Chuu-Lian Terng Affiliation: University of California, Irvine Date: September 17, 2022 In this talk, I will explain some applications of

From playlist Glimpses of Mathematics, Now and Then: A Celebration of Karen Uhlenbeck's 80th Birthday

Video thumbnail

Physics - Thermodynamics: (9 of 22) Change Of State: Constant Volume (Isovolumetric)

Visit http://ilectureonline.com for more math and science lectures! In this video I will explain the change of state of a constant volume or isovolumetric (isochoric) process.

From playlist PHYSICS - THERMODYNAMICS

Related pages

Cubic crystal system | Density | Isotropy | Homogeneity (physics)