Unified interatomic potential and energy barrier distributions for amorphous oxides

Trinastic, J.; Hamdan, Rashid; Wu, Yu‐Ning; Zhang, L.; Cheng, Hai‐Ping

doi:10.1063/1.4825197

Cited by 39 publications

(21 citation statements)

References 78 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28 In this procedure, the crystalline system is heated up from 300 K to 6000 K over a period of 160 ps using an isobaric-isothermal ensemble (NPT) where temperature is increased at a constant rate. After a period of equilibration at 6000 K within a canonical, constant volume and constant temperature ensemble (NVT), the procedure is reversed and the system is cooled down slowly to room temperature.…”

Section: Methodsmentioning

confidence: 99%

Molecular dynamics study of the mechanical loss in amorphous pure and doped silica

Hamdan

Trinastic

Cheng

2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

Gravitational wave detectors and other precision measurement devices are limited by the thermal noise in the oxide coatings on the mirrors of such devices. We have investigated the mechanical loss in amorphous oxides by calculating the internal friction using classical, atomistic molecular dynamics simulations. We have implemented the trajectory bisection method and the non-local ridge method in the DL-POLY molecular dynamics simulation software to carry out those calculations. These methods have been used to locate the local potential energy minima that a system visits during a molecular dynamics trajectory and the transition state between any two consecutive minima. Using the numerically calculated barrier height distributions, barrier asymmetry distributions, relaxation times, and deformation potentials, we have calculated the internal friction of pure amorphous silica and silica mixed with other oxides. The results for silica compare well with experiment. Finally, we use the numerical calculations to comment on the validity of previously used theoretical assumptions.

show abstract

Section: Methodsmentioning

confidence: 99%

Molecular dynamics study of the mechanical loss in amorphous pure and doped silica

Hamdan

Trinastic

Cheng

2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…29 The last term is the Morse potential, added to better model the partially covalent interaction between anions and cations in these oxides. 27 Only electrostatic forces describe cation-cation interactions, which allows for mixing of different oxides without adjusting the force field parameters.…”

Section: A Theory Of Two-level Systems and Internal Frictionmentioning

confidence: 99%

Molecular dynamics modeling of mechanical loss in amorphous tantala and titania-doped tantala

2016

Self Cite

View full text Add to dashboard Cite

The mechanical loss (Q −1 ) intrinsic to amorphous oxides is the limiting factor for sensitive, high-precision gravitational wave detectors and optical devices. Recent experimental work suggests that doping amorphous tantala with titania reduces Q −1 , however the physical processes underlying this reduction are unknown. Here we calculate Q −1 for pure and titania-doped tantala using numerical methods combined with molecular dynamics simulations that have atomic levels of resolution. Our results match experimental trends that titania doping decreases the magnitude of the low-temperature loss peak characteristic of these materials, with 62% titanium cation doping minimizing Q −1 at low temperature. We provide a microscopic explanation for this reduced loss by examining how doping affects the potential energy landscape, strain coupling constant, relaxation time, and other properties of the amorphous materials within the framework of the double well potential model. Analyzing configurational changes provides the first atomic description of the transitions driving mechanical loss at various temperatures in these oxides. These results identify the important parameters contributing to Q −1 that are most affected by doping and provide guidance for how to screen for optimal doping combinations to minimize loss in other materials.

show abstract

“…through molecular dynamics simulations [16]. However, the amount of knowledge available to date seems insufficient to exploit this pathway to engineer glassy mixtures of oxides with given viscoelastic and optical properties.…”

Section: A State Of the Art: A Concise Surveymentioning

confidence: 99%

The AdCoat project coatings for gravitational antennas of second and third generation

Canepa

2014

2014 IEEE Metrology for Aerospace (MetroAeroSpace)

View full text Add to dashboard Cite

A relevant example where systems simultaneously capable of quasi ideal reflectivity and extremely low mechanical dissipation play a critical role, is provided by the test masses used in the gravitational waves detectors interferometers. Thermal noise generated by dissipation in the test-masses is the dominating factor in a frequency band, between 50 Hz and a few hundreds Hz, where a high relative sensitivity of the instrument meets a high astrophysical interest. The choice of interferential mirrors (e.g. λ 4 Ta2O5-SiO2 multilayers) negatively impacts on thermal noise as the mechanical losses in the coating are relatively large. Only a substantial reduction of the thermal noise of the mirrors will allow GWDs to reach and possibly exceed the limit represented by the quantum noise. This contribution aims at illustrating AdCoat a nation-wide research program recently launched by INFN, which attempts to gather all groups working in Italy on the reduction of thermal noise in coatings for gravitational antennas of second and third generation.

show abstract

Unified interatomic potential and energy barrier distributions for amorphous oxides

Cited by 39 publications

References 78 publications

Molecular dynamics study of the mechanical loss in amorphous pure and doped silica

Molecular dynamics study of the mechanical loss in amorphous pure and doped silica

Molecular dynamics modeling of mechanical loss in amorphous tantala and titania-doped tantala

The AdCoat project coatings for gravitational antennas of second and third generation

Contact Info

Product

Resources

About