# Internal friction - wide range
⏎
⏎
- 2006 [Universal behavior of internal friction in glasses below Tg : anharmonicity vs relaxation](https://arxiv.org/pdf/cond-mat/0610693.pdf)
⏎
**diffs between strong and fragile glasses - the relative role of defects?**
⏎
1999 [Theory of Sound Attenuation in Glasses: The Role of Thermal Vibrations](https://epub.uni-regensburg.de/1832/1/fabian22.pdf)
⏎
- [Internal friction universality - RevModPhys](https://knowen-production.s3.amazonaws.com/uploads/attachment/file/5377/2002%2B-%2BPohl%2B-%2Brevmodphys.74.991.pdf)
⏎
- Internal friction plot - 1986 [Low temperature properties of glasses-unsolved problems - A K RAYCHAUDHURI](https://www.ias.ac.in/article/fulltext/jcsc/096/06/0559-0564)
⏎
![cc](https://knowen-production.s3.amazonaws.com/uploads/attachment/file/5475/friction.png 'bb')
⏎
## crystals vs glasses?
⏎
⏎
⏎
⏎
# Parents
⏎
* Small d-less coupling- $\lambda/l$ ratio - P⏎