A Comparison of the Electron and Ion Irradiation Effects on the：在电子和离子束辐照效应的比较.ppt

PARISON OF THE ELECTRON AND ION IRRADIATION EFFECTS ON THE STABILITY RANGE OF ORDERED STRUCTURES IN Ni4 Mo
M. SUNDARARAMAN* and S. BANERJEE
Presented by G. K. DEY
Materials Science Division
Bhabha Atomic Research Division
Mumbai 400085
* email:******@..in
Outline
Ordering – chemical, ic, & electric
Evolution of Ordering
Competing superlattices in Ni4Mo alloy
Influence of radiation on order  disorder
Order evolution
-- under electron irradiation
-- under heavy ion parison of electron and ion irradiation results
Conclusions
Ordering – Chemical, ic, ferroelectric
Chemical Ordering
ic
Ferroelectric Ordering
Empty
lattice
Atoms A & B
Electric/
ic
moments
Evolution of order
Nucleation and Growth
Continuous Ordering
Order evolution could be either first or second order
Evolution of Ordering: Discrete Mode
(Nucleation & Growth)
Nucleation
Disordered
Matrix
Evolution of Ordering – Static Concentration Waves
Single Variant <100>
K vector – B2 Ordering
3 variants <100> K vector
– L12 ordering
Continuous Ordering
Amplification of concentration wave with time
First & second order transitions: Thermodynamic viewpoint
nth order transformation:
F
E
Cp
Temperature 
First Order Second order
Energy barrier
Nucleation & growth
First & second order transitions: Landau Plots
First Order
(Discrete)
Second order
(Continuous)