Recent content by qwerasadf
-
Q
The piezoelectric effect in ferroelectrics
Or let's say: What is the exact reason for the inverse piezoeffect (strain) in ferroelectrics? And what is the exact reason for the pieoeffect in ferroelectrics? Augmentation of Polarization in every unit cell or the movement of the domains resulting in augmentation in polarization?- qwerasadf
- Post #3
- Forum: Materials and Chemical Engineering
-
Q
The piezoelectric effect in ferroelectrics
The short version of the main issue is: Do the movements of 90° domains contribute to the typical large strain in piezo ferroelectrics upon an applied electric field? Do the movements of 90° domains contribute to the voltage upon a mechanical stress?- qwerasadf
- Post #2
- Forum: Materials and Chemical Engineering
-
Q
The piezoelectric effect in ferroelectrics
Hey, I am confused, what is the exact reason for the appearance of a voltage upon a mechanical stress at a ferroelectric material like a BaTiO3 Perovskite? Below the Curie temperature the structure is no more cubic but tetragonal, let's say c-site is now longer than a- and b-site. And of course...- qwerasadf
- Thread
- Piezoelectric
- Replies: 2
- Forum: Materials and Chemical Engineering
-
Q
Graduate Temperature dependence of relaxation time T1 vs T2
In this picture we can see the spectral density with different frequencies. If there are are high dynamics => shorter correlation time => frequency distribution becomes broader. the dashed lines is referred to the T1 relaxation time. T2 is at 0Hz. Thus, increasing dynamics lead to low T2, right?- qwerasadf
- Post #5
- Forum: Atomic and Condensed Matter
-
Q
Graduate Temperature dependence of relaxation time T1 vs T2
Hi, DrClaude, Its about the investigation of Relaxor ferroelectrics with NMR relaxation time.- qwerasadf
- Post #3
- Forum: Atomic and Condensed Matter
-
Q
Graduate Temperature dependence of relaxation time T1 vs T2
Hi, when we assume a obejct with increasing dynamics with increasing temperature, the longitudinal relaxation time T1 should decrease. Since we have, let's say at a frequency 100 MHz , more fluctuations of B0. Ok, then the transversal relaxation time T2 must increase with increasing...- qwerasadf
- Thread
- Relaxation time Temperature Temperature dependence Time
- Replies: 5
- Forum: Atomic and Condensed Matter