386
20 Wonders of Multifield Lattice Oscillation
where ω i < ω. The n i is the population function of ω i selected from the thermal
bath. The c and c i are adjustable weighting factors.
Although Eqs. (20.10)–(20.11) reproduce equally well the ω(T) for diamond
and silicon, the physical indication of the adjustable weighting factors is unclear.
20.5 Motivation and Objectives
Phonon spectroscopy is a widely-used tool of detection but the conventional
approaches of spectral peak Gaussian decomposition or the empirical simulation
of the spectral feature evolution under perturbation limited its advantage in revealing
the bonding dynamics. One often simply decomposes a spectral peak into multiple
Gaussian components with limited constraints albeit physical indications or simulates
the spectral peak evolution in an empirical manner with multiple freely adjustable
variables. Conventional phonon spectroscopy analysis has delivered information far
less than it is supposed to be because of lacking the phonon-bond-stimulus correlation
functions. The Grüneisen constant is an experimental derivative showing the linear
dependence of the frequency shift on the stimulus. The optical phonon degeneration
and the multiple phonon resonant scatting are extrinsic artifacts exist throughout the
processes of experiments.
The key challenge is a theory to reproduce observations because of bond relaxation
in length and energy and the bond-phonon-property correlation of the examined
substance to reconcile as many as perturbations to the phonon frequency shift in terms
of excited bond relaxation. One needs to correlate the ω, Γ , A (abundance)
intrinsically to the bond length an energy relaxed by external stimuli. Therefore, bond
relaxation is profoundly and ubiquitously important to the engineering of materials
and thus should receive deserved attention.
This part is devoted to modeling the multifield lattice oscillation in the past decade
to meet the following targets:
(1) Theoretical reproduction of the phonon spectroscopy measurements with
physically meaningful parameters.
(2) Provision of atomistic, local, quantitative, elemental information on bonding
dynamics from measurements.
(3) Comprehension of the physical mechanism and basic rules governing observations.
(4) Correlation of the detectable quantities, Q(x i )/Q(x i0 ) = f(x i , d(x i ), E(x i )), to
the bond length and energy that relax upon perturbation by the degree of freedom
x i .
This part deals with the multifield lattice oscillation dynamics to amplify the
Coordination-resolved Electron Spectrometrics [6, 118] and its analytical strategies
to the current Multifield Phonon Spectrometrics [119–121] for consistent insight
into phonon relaxation with derivative of conventionally-unexpected quantitative
information. From the perspective of the local bond averaging (LBA) approach [7],
20 Wonders of Multifield Lattice Oscillation
where ω i < ω. The n i is the population function of ω i selected from the thermal
bath. The c and c i are adjustable weighting factors.
Although Eqs. (20.10)–(20.11) reproduce equally well the ω(T) for diamond
and silicon, the physical indication of the adjustable weighting factors is unclear.
20.5 Motivation and Objectives
Phonon spectroscopy is a widely-used tool of detection but the conventional
approaches of spectral peak Gaussian decomposition or the empirical simulation
of the spectral feature evolution under perturbation limited its advantage in revealing
the bonding dynamics. One often simply decomposes a spectral peak into multiple
Gaussian components with limited constraints albeit physical indications or simulates
the spectral peak evolution in an empirical manner with multiple freely adjustable
variables. Conventional phonon spectroscopy analysis has delivered information far
less than it is supposed to be because of lacking the phonon-bond-stimulus correlation
functions. The Grüneisen constant is an experimental derivative showing the linear
dependence of the frequency shift on the stimulus. The optical phonon degeneration
and the multiple phonon resonant scatting are extrinsic artifacts exist throughout the
processes of experiments.
The key challenge is a theory to reproduce observations because of bond relaxation
in length and energy and the bond-phonon-property correlation of the examined
substance to reconcile as many as perturbations to the phonon frequency shift in terms
of excited bond relaxation. One needs to correlate the ω, Γ , A (abundance)
intrinsically to the bond length an energy relaxed by external stimuli. Therefore, bond
relaxation is profoundly and ubiquitously important to the engineering of materials
and thus should receive deserved attention.
This part is devoted to modeling the multifield lattice oscillation in the past decade
to meet the following targets:
(1) Theoretical reproduction of the phonon spectroscopy measurements with
physically meaningful parameters.
(2) Provision of atomistic, local, quantitative, elemental information on bonding
dynamics from measurements.
(3) Comprehension of the physical mechanism and basic rules governing observations.
(4) Correlation of the detectable quantities, Q(x i )/Q(x i0 ) = f(x i , d(x i ), E(x i )), to
the bond length and energy that relax upon perturbation by the degree of freedom
x i .
This part deals with the multifield lattice oscillation dynamics to amplify the
Coordination-resolved Electron Spectrometrics [6, 118] and its analytical strategies
to the current Multifield Phonon Spectrometrics [119–121] for consistent insight
into phonon relaxation with derivative of conventionally-unexpected quantitative
information. From the perspective of the local bond averaging (LBA) approach [7],