| Autor: |
Gonzales, Justin, Gajare, Siddhesh, Nguyen, Sophie, Wu, Alicia, Newman, Nathan |
| Předmět: |
|
| Zdroj: |
Applied Physics Letters; 11/30/2020, Vol. 117 Issue 22, p1-6, 6p |
| Abstrakt: |
In 2012, we demonstrated that microwave loss in practical microwave dielectrics is dominated by electron paramagnetic resonance transitions at cryogenic temperatures. We later used this understanding to develop "smart" materials that switch Fe-doped Al2O3 (εr = 9.8) dielectric ceramics between a low-loss "on state" and a high-loss "off state" at frequencies of ∼12 and ∼19 GHz with a small magnetic field (<100 G). In this report, we extend our work on smart materials to the large dielectric constant (εr = 24) host La(Al1−xFex)O3 so that it can be used in compact resonator and filter designs operating at ∼4 GHz to ∼7 GHz. The Fe3+ ions' zero-field splitting energies are determined by the crystal-field parameters D = 1.55 GHz and E = 0 GHz, along with significant contributions from the higher-order terms, B 4 0 (−6.467 MHz) and B 4 3 (160 MHz). These switchable dielectrics may have applications in future communication and Doppler technology. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
