scholarly journals A molecular dynamics study on lubricant perfluoropolyether in hard disk driver

2005 ◽  
Vol 54 (8) ◽  
pp. 3787
Author(s):  
Li Xin ◽  
Hu Yuan-Zhong ◽  
Wang Hui
Keyword(s):  
Molecular Dynamics ◽  
Hard Disk ◽  
Hard Disk Driver

Molecular dynamics studies of two hard-disk particles in a rectangular box I. Thermodynamic properties and position autocorrelation functions

2004 ◽  
Vol 21 (2) ◽  
pp. 504-510 ◽  
Author(s):  
Soong-Hyuck Suh ◽  
Jae-Wook Lee ◽  
Hee Moon ◽  
James M. D. MacElroy
Keyword(s):  
Molecular Dynamics ◽  
Thermodynamic Properties ◽  
Hard Disk ◽  
Autocorrelation Functions

scholarly journals Study of the Thermal Decomposition of PFPEs Lubricants on a Thin DLC Film Using Finitely Extensible Nonlinear Elastic Potential Based Molecular Dynamics Simulation

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
S. K. Deb Nath ◽  
C. H. Wong
Keyword(s):  
Molecular Dynamics ◽  
Hard Disk ◽  
Elastic Potential ◽  
Dynamics Simulation ◽  
Coarse Grained ◽  
Spring Model ◽  
Disk Interface ◽  
End Groups ◽  
Effects Of Temperature ◽  
Nonlinear Elastic

Perfluoropolyethers (PFPEs) are widely used as hard disk lubricants for protecting carbon overcoat reducing friction between the hard disk interface and the head during the movement of head during reading and writing data in the hard disk. Due to temperature rise of PFPE Zdol lubricant molecules on a DLC surface, how polar end groups are detached from lubricant molecules during coating is described considering the effect of temperatures on the bond/break density of PFPE Zdol using the coarse-grained bead spring model based on finitely extensible nonlinear elastic potential. As PFPE Z contains no polar end groups, effects of temperature on the bond/break density (number of broken bonds/total number of bonds) are not so significant like PFPE Zdol. Effects of temperature on the bond/break density of PFPE Z on DLC surface are also discussed with the help of graphical results. How bond/break phenomenonaffects the end bead density of PFPE Z and PFPE Zdol on DLC surface is discussed elaborately. How the overall bond length of PFPE Zdol increases with the increase of temperature which is responsible for its decomposition is discussed with the help of graphical results. At HAMR condition, as PFPE Z and PFPE Zdol are not suitable lubricant on a hard disk surface, it needs more investigations to obtain suitable lubricant. We study the effect of breaking of bonds of nonfunctional lubricant PFPE Z, functional lubricants such as PFPE Zdol and PFPE Ztetrao, and multidented functional lubricants such as ARJ-DS, ARJ-DD, and OHJ-DS on a DLC substrate with the increase of temperature when heating of all of the lubricants on a DLC substrate is carried out isothermally using the coarse-grained bead spring model by molecular dynamics simulations and suitable lubricant is selected which is suitable on a DLC substrate at high temperature.

Vibration suppression of a hard disk driver actuator arm using piezoelectric shunt damping with a topology-optimized PZT transducer

2009 ◽  
Vol 18 (6) ◽  
pp. 065010 ◽  
Author(s):  
Hao Sun ◽  
Zhichun Yang ◽  
KaiXiang Li ◽  
Bin Li ◽  
Jiang Xie ◽  
...  
Keyword(s):  
Vibration Suppression ◽  
Hard Disk ◽  
Shunt Damping ◽  
Hard Disk Driver ◽  
Piezoelectric Shunt

A GENERALIZED CELL METHOD FOR HARD DISK MOLECULAR DYNAMICS SIMULATION OF POLYDISPERSE SYSTEMS

2007 ◽  
Vol 18 (09) ◽  
pp. 1407-1416
Author(s):  
MEVLUT BULUT ◽  
RENATO P. CAMATA
Keyword(s):  
Molecular Dynamics ◽  
Cell Size ◽  
Hard Disk ◽  
Significant Loss ◽  
Three Dimensions ◽  
Dynamics Simulation ◽  
Collision Rate ◽  
Canonical Systems ◽  
Size Criterion ◽  
Number Of Particles

Hard Disk Molecular Dynamics (HDMD) techniques often exhibit significant loss in calculation speed when applied to the simulation of highly polydisperse particle systems. The collision rate of the reported algorithms may be lower by as much as two orders of magnitude if compared to the collision rate of a monodisperse system of the same number of particles. This is mainly due to the fact that the rectangular cells in the simulation domain used in HDMD methods must meet a certain size criterion. In this paper, we introduce a cell technique that removes the requirement on the cell size enabling simulation of particles with sizes much larger than the cell size. This approach improves the collision rates in the simulation of tested polydisperse systems by factors ranging from 5.5 to 57 depending on the size distribution of the particle population simulated. This may enable the simulation of grand canonical systems in which the size and the number of particles can change throughout the simulation. The technique is compatible with the simulation of disk-like as well as irregularly shaped particles and can be extended to three dimensions.

SIMPLE AND EFFICIENT ALGORITHM FOR LARGE SCALE MOLECULAR DYNAMICS SIMULATION IN HARD DISK SYSTEM

1999 ◽  
Vol 10 (07) ◽  
pp. 1281-1293 ◽  
Author(s):  
MASAHARU ISOBE
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Efficient Algorithm ◽  
Large Scale ◽  
Particle System ◽  
Hard Disk ◽  
Dynamics Simulation ◽  
Space System ◽  
Disk System ◽  
Analysis Of Algorithm

A simple and efficient algorithm of the molecular-dynamics simulation of the hard disk system based on the Event-Driven method is developed. From the analysis of algorithm, the complexity is [Formula: see text] per 1 event, and the constant coefficient of the complexity is smaller than conventional efficient algorithm based on the concept of Cell-Crossing Event. The maximum performance of more than 460 millions of collisions per CPU-hour on the Alpha600 compatible in a 2500 particle system is achieved. An extension to the infinite-space system based on this algorithm is also proposed.

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