Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method
It is essential to clarify the interaction between the magnetic head and the monolayer lubricant film coated on the magnetic disk in the design of next-generation hard disk drives with ultra-low flying height. However, with previous measuring methods such as AFM, it was difficult to measure the mech...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Japanese Society of Tribologists
2011-01-01
|
| Series: | Tribology Online |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/trol/6/1/6_1_83/_pdf/-char/en |
| _version_ | 1818842719642976256 |
|---|---|
| author | Yuya Hamamoto Shintaro Itoh Kenji Fukuzawa Hedong Zhang |
| author_facet | Yuya Hamamoto Shintaro Itoh Kenji Fukuzawa Hedong Zhang |
| author_sort | Yuya Hamamoto |
| collection | DOAJ |
| description | It is essential to clarify the interaction between the magnetic head and the monolayer lubricant film coated on the magnetic disk in the design of next-generation hard disk drives with ultra-low flying height. However, with previous measuring methods such as AFM, it was difficult to measure the mechanical properties of molecularly thin lubricant films with a precisely controlled nanometer-sized gaps. In this study, we applied the fiber wobbling method to clarify the viscoelastic properties of monolayer lubricant films during touch-down and take-off behavior. The fiber wobbling method is the highly-sensitive measurement of shear force we developed and can control the shearing gap with sub-nanometer resolution. The gap dependence of viscoelastic properties was evaluated both in the approaching and the separating processes and their differences and dependencies on the types of lubricant films were discussed. As sample lubricants, we used non-polar and polar perfluoropolyether lubricants: Fomblin Z03 and Fomblin Zdol4000. Three different types of monolayer lubricant films were prepared. The first one consisted of mobile molecules of Z03 only. The second one contained both mobile and bonded molecules of Zdol4000. The third one was only made of bonded molecules of Zdol4000. Our experimental results indicated that the mobile molecules caused the formation of a liquid bridge between solid surfaces and it leads to the hysteresis of viscoelastic properties between approaching and separating processes. On the other hand, the sample only consisted of bonded molecules did not show such a hysteresis. |
| first_indexed | 2024-12-19T04:46:27Z |
| format | Article |
| id | doaj.art-0500a49c50944583ac02a23276597887 |
| institution | Directory Open Access Journal |
| issn | 1881-2198 |
| language | English |
| last_indexed | 2024-12-19T04:46:27Z |
| publishDate | 2011-01-01 |
| publisher | Japanese Society of Tribologists |
| record_format | Article |
| series | Tribology Online |
| spelling | doaj.art-0500a49c50944583ac02a232765978872022-12-21T20:35:29ZengJapanese Society of TribologistsTribology Online1881-21982011-01-0161839510.2474/trol.6.83trolViscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling MethodYuya Hamamoto0Shintaro Itoh1Kenji Fukuzawa2Hedong Zhang3Department of Mechanical and Science Engineering, Nagoya UniversityDepartment of Mechanical and Science Engineering, Nagoya UniversityDepartment of Mechanical and Science Engineering, Nagoya UniversityDepartment of Complex Systems Science, Nagoya UniversityIt is essential to clarify the interaction between the magnetic head and the monolayer lubricant film coated on the magnetic disk in the design of next-generation hard disk drives with ultra-low flying height. However, with previous measuring methods such as AFM, it was difficult to measure the mechanical properties of molecularly thin lubricant films with a precisely controlled nanometer-sized gaps. In this study, we applied the fiber wobbling method to clarify the viscoelastic properties of monolayer lubricant films during touch-down and take-off behavior. The fiber wobbling method is the highly-sensitive measurement of shear force we developed and can control the shearing gap with sub-nanometer resolution. The gap dependence of viscoelastic properties was evaluated both in the approaching and the separating processes and their differences and dependencies on the types of lubricant films were discussed. As sample lubricants, we used non-polar and polar perfluoropolyether lubricants: Fomblin Z03 and Fomblin Zdol4000. Three different types of monolayer lubricant films were prepared. The first one consisted of mobile molecules of Z03 only. The second one contained both mobile and bonded molecules of Zdol4000. The third one was only made of bonded molecules of Zdol4000. Our experimental results indicated that the mobile molecules caused the formation of a liquid bridge between solid surfaces and it leads to the hysteresis of viscoelastic properties between approaching and separating processes. On the other hand, the sample only consisted of bonded molecules did not show such a hysteresis.https://www.jstage.jst.go.jp/article/trol/6/1/6_1_83/_pdf/-char/ennano-rheologynano-tribologyviscoelastic measurementhead-disk interfacemolecularly thin filmliquid bridge |
| spellingShingle | Yuya Hamamoto Shintaro Itoh Kenji Fukuzawa Hedong Zhang Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method Tribology Online nano-rheology nano-tribology viscoelastic measurement head-disk interface molecularly thin film liquid bridge |
| title | Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method |
| title_full | Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method |
| title_fullStr | Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method |
| title_full_unstemmed | Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method |
| title_short | Viscoelastic Properties of Monolayer Lubricant Films during Touch-Down and Take-Off Behavior Measured by Fiber Wobbling Method |
| title_sort | viscoelastic properties of monolayer lubricant films during touch down and take off behavior measured by fiber wobbling method |
| topic | nano-rheology nano-tribology viscoelastic measurement head-disk interface molecularly thin film liquid bridge |
| url | https://www.jstage.jst.go.jp/article/trol/6/1/6_1_83/_pdf/-char/en |
| work_keys_str_mv | AT yuyahamamoto viscoelasticpropertiesofmonolayerlubricantfilmsduringtouchdownandtakeoffbehaviormeasuredbyfiberwobblingmethod AT shintaroitoh viscoelasticpropertiesofmonolayerlubricantfilmsduringtouchdownandtakeoffbehaviormeasuredbyfiberwobblingmethod AT kenjifukuzawa viscoelasticpropertiesofmonolayerlubricantfilmsduringtouchdownandtakeoffbehaviormeasuredbyfiberwobblingmethod AT hedongzhang viscoelasticpropertiesofmonolayerlubricantfilmsduringtouchdownandtakeoffbehaviormeasuredbyfiberwobblingmethod |