CH1105: Materials Science Crystal Structure Assoc/Prof Timothy Tan Office: N1.2 B2-34 B2Tel: 6316 8829 E-mail: tytan@ntu.edu.sg Semester 1‚ 2013-2014 2013School of Chemical and Biomedical Engineering Why study structure of crystalline solids? To understand how atoms assemble geometrically into solid structures To describe the structure of solids To relate material properties to its structure 2 Energy and Packing Dense‚ regular packing Energy typical neighbor bond length typical
Premium Crystallography Crystal system Crystal structure
Learning Log 2: Observe‚ Connect and Reflect on Your Learning PART III – Symmetry in Crystals The most striking examples of symmetry…are crystals. Herman Weyl Study Period Focus Image Question Your Observations Week 5 Image 5 What observations can you make about these octahedra of cubic cristobalite‚ another polymorph of quartz‚ ‘frozen’ in volcanic glass? (no more than 50 words) (2 marks) What is your personal favourite gemstone and what is its space group. (around 10 words) (2 marks)
Premium Quartz Mineral Knowledge
GROUP A MODEL ANSWER Howard et al.‚ Temperature-induced structural changes in CaCl2‚ CaBr2 and CrCl2: A synchrotron X-ray powder diffraction Phys. Rev. B 72‚ 214114 (2005). DO NOT PLAGIARISE THIS MODEL ANSWER Paragraph 1 This article concerns about 2 polymorph structures that is associated with temperature-induced structural transitions. One of the structure being studied is the orthorhombic structure‚ or sometimes referred to as the calcium chloride structure‚ that is observed before the transition
Premium Crystallography
GROUP A MODEL ANSWER Yoshida et al.‚ Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton Conductor‚ Symmetry 2012‚ 4‚ 507-516. DO NOT PLAGIARISE THIS MODEL ANSWER PLAGIARISM FROM ANY SOURCE AUTOMATICALLY LEADS TO A ZERO SCORE Paragraph 1 There are three phases whereby each has a different crystal structure at three different temperatures. At room temperature (298K)‚ Phase III is present whereby Cs3H(SeO4)2 has a crystal structure of a monoclinic with a space group of C2/m. At
Premium Hydrogen Crystallography Crystal system
Unit-1 THE SOLID STATE QUESTIONS VSA QUESTIONS (1 - MARK QUESTIONS) 1. 2. 3. 4. 8. 9. What are anistropic substances. Why are amorphous solids isotropic in nature? Why glass is regarded as an amorphous solid? Define the term ’crystal lattice.’ Define the term voids. What type of stochiometric defect is shown by (i) ZnS and (ii) CsCl? [Hint. : (i) Frenkel defect (ii) Schottky defect] *10. If the formula of a compound is A2B‚ which sites would be occupied by A ions? [Hint. : Number of A ions is
Premium Crystal system Crystal Solid
Paragraph 1 The research paper written by Haines et al. concerns the investigation of structural and chemical properties of quartz-type FePO4‚ where observations are made regarding the quartz-type FePO4 at elevated temperatures and during the occurrence of the α- β transition stage. The temperature range that was selected for the investigation was from 294K to 1073K and the investigation was carried out by neutron powder diffraction. The properties of the quartz-type FePO4 was compared to other α-quartz
Premium Crystal structure Solid Crystallography
Engineering Materials Week 2 3.1 What is the difference between atomic structure and crystal structure? Atomic structure relates to the number of protons and neutrons in the nucleus of an atom. Crystal structure pertains to the arrangement of atoms in the crystalline solid material. 3.9 Calculate the radius of a tantalum atom‚ given that Ta has an BCC crystal structure‚ a density of 16.6 g/cm^3‚ and an atomic weight of 180.9 g/mol. For BCC n=2 atoms/unit cell 3.47 Below are shown three different
Premium Crystallography Crystal Crystal system
Group A: Model Answer GROUP A MODEL ANSWER Yoshida et al.‚ Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton Conductor‚ Symmetry 2012‚ 4‚ 507-516. DO NOT PLAGIARISE THIS MODEL ANSWER PLAGIARISM FROM ANY SOURCE AUTOMATICALLY LEADS TO A ZERO SCORE Paragraph 1 There are three phases whereby each has a different crystal structure at three different temperatures. At room temperature (298K)‚ Phase III is present whereby Cs3H(SeO4)2 has a crystal structure of a monoclinic
Premium Hydrogen Atom Crystallography
Paragraph 1: Temperature; driver for the change of symmetry There are 3 different phases that are observed and each of them are influenced by temperature. In addition‚ in each phase‚ the polymorph exhibits different crystal structures. At room temperature of 298K‚ it will be in phase 3 where it takes the structure of monoclinic-C2/m. When the temperature rises to 396K‚ it undergoes a transition into Phase 2 also known as the high-temperature monoclinic-A2/a phase. At Phase 2‚ the lattice parameters
Premium Crystal structure Energy Atom
Yoshida et al.‚ Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton Conductor‚ Symmetry 2012‚ 4‚ 507-516. Paragraph 1 In this paper‚ we take a look at the different phases of the Cs3H(SeO4)2 polymorphs. There are 3 different phases that is observed and each of them is influenced by the temperatures. In addition‚ in each phase‚ the polymorph exhibits different crystal structure. At the room temperature of 298K‚ it will be in phase 3 whereby it takes the structure of monoclinic-C2/m
Premium Hydrogen Crystal system Fuel cell