| Summary: | 碩士 === 國立臺灣大學 === 物理學研究所 === 87 === Abstract
We report the magnetization, magneto-resistance and Hall coefficient of epitaxial SrRuO3 films
n SrTiO3 (110) and (001) substrates under varied temperatures and magnetic fields in paramagnetic
and ferromagnetic states. The SrRuO3 films were grown in-situ by the radio frequency magnetron
sputtering technique. The Hall coefficient RH is positive when the temperature is greater than the
sign reversal temperature, Tr and reverts to negative when the temperature is below Tr. The Hall
resistivity rxy in the paramagnetic state follows the behavior (1 － T/TC)-1. The spontaneous Hall
coefficient Rs is negative when the temperature is below T = 130 K. We used the theory of the
spontaneous Hall coefficient proposed by Kondo in the paramagnetic state and the theory of the
spontaneous Hall coefficient proposed by Irkhin etal. in the ferromagnetic state to discuss its
temperature behavior. The analyzed data suggest that the mixed interaction of spin-orbital o
f the magnetic electrons in SrRuO3 films play an essential role in the occurrence of the negative
value of Rs.
On the other hand, YBa2Cu3O7-X/SrRuO3 (96 nm/96 nm) film show ferromagnetic transition
at T ~150 K and is superconducting at T = 35 K. The Hall coefficient, RH, is positive at high
temperature (T > 125 K). In the negative Hall coefficient regime, the RH decreases and enters a
local minimum and reverts to zero at low temperatures for YBa2Cu3O7-X/SrRuO3 films. The
pinning characteristic of YBa2Cu3O7-X/SrRuO3 films was discussed in terms of the exiting
pinning theories.
1. J. Kondo, Prog. Theoeret. Phys., (Japan) 27, 772 (1962).
2. Yu. P. Irkhin et al., Phys. Stat. Sol. 22, 309, (1967).
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