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Title: High pressure structural behavior of YGa{sub 2}: A combined experimental and theoretical study

High pressure structural stability studies were carried out on YGa{sub 2} (AlB{sub 2} type structure at NTP, space group P6/mmm) up to a pressure of ~35 GPa using both laboratory based rotating anode and synchrotron X-ray sources. An isostructural transition with reduced c/a ratio, was observed at ~6 GPa and above ~17.5 GPa, the compound transformed to orthorhombic structure. Bulk modulus B{sub 0} for the parent and high pressure phases were estimated using Birch–Murnaghan and modified Birch–Murnaghan equation of state. Electronic structure calculations based on projector augmented wave method confirms the experimentally observed two high pressure structural transitions. The calculations also reveal that the ‘Ga’ networks remains as two dimensional in the high pressure isostructural phase, whereas the orthorhombic phase involves three dimensional networks of ‘Ga’ atoms interconnected by strong covalent bonds. - Graphical abstract: High pressure X-ray diffraction patterns of YGa{sub 2} up to ~35 GPa shows an isostructural phase transition at ~5 GPa and transition to an orthorhombic structure ~14 GPa. - Highlights: • High pressure structural stability studies were carried out on YGa{sub 2} up to 35 GPa. • An isostructural transition with reduced c/a ratio was observed above 6 GPa. • Above 17.5 GPa, the compoundmore » transformed to orthorhombic structure. • PAW based electronic structure calculations have been carried out. • Calculations confirm the experimentally observed structural transitions.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ; ; ;  [3] ; ; ;  [4] ;  [5]
  1. Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu (India)
  2. Chemical Group@, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu (India)
  3. Indus Synchrotron Utilization Division, Raja Ramanna Center for Advanced Technology, Indore-452013 (India)
  4. Advanced Centre for Research in High Energy Materials, University of Hyderabad, Gachibowli, Hyderabad-500046, Telangana (India)
  5. Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502 205, Telangana (India)
Publication Date:
OSTI Identifier:
22475630
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 226; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM BORIDES; CHEMICAL BONDS; ELECTRONIC STRUCTURE; EQUATIONS OF STATE; GALLIUM BASE ALLOYS; HEXAGONAL LATTICES; ORTHORHOMBIC LATTICES; PHASE TRANSFORMATIONS; PRESSURE DEPENDENCE; PRESSURE RANGE GIGA PA; TWO-DIMENSIONAL SYSTEMS; X-RAY DIFFRACTION; YTTRIUM ALLOYS