LSMO/STO/LSMO Manyetik Tünel Ekleminin Zayıf Manyetik Alanlarda Tünelleme Manyetodirenci

Darbeli lazer biriktirme tekniği kullanılarak La0.7Sr0.3MnO3/SrTiO3/La0.7Sr0.3MnO3 manyetik tünel eklemiSrTiO3alttaş üzerinde büyütüldü. Ferromanyetik elektrot için La0.7Sr0.3MnO3 (LSMO) ve tünelleme bariyeri için SrTiO3 (STO) kullanıldı. Sıcaklığın ve manyetik alanın elektriksel özelliklere etkisi araştırıldı. Alt elektrot ve eklemdirençlerinin çok güçlü bir şekilde sıcaklığa bağlı olduğu gözlemlendi. 77.3 K sıcaklık ve zayıf manyetik alanlardayaklaşık % 300’lük yüksek manyetodirenç gözlemlendi. Gözlemlenen yüksek manyetodirenç La0.7Sr0.3MnO3’ünyarımetalik band yapısından kaynaklanır. TMR eğrilerinin asimetrik yapısı, farklı kalınlıktaki elektrotlar ile üst vealt STO/LSMO ara yüzeylerin elektronik yapılarının farklılığına atfedildi

Anahtar Kelimeler:

La 0.7Sr0.3MnO3, manyetik tünel eklemi, spintronik, tünelleme manyetodirenci

Tunnelling Magnetoresistance at Low Magnetic Fields in LSMO/STO/LSMO Magnetic Tunnel Junction

La0.7Sr0.3MnO3/SrTiO3/La0.7Sr0.3MnO3 magnetic tunnel junction was grown on (001)-oriented SrTiO3 substrate by using pulsed laser deposition technique. La0.7Sr0.3MnO3 (LSMO) was used as ferromagnetic(FM) electrodes and SrTiO3 (STO) was used as a tunnel barrier. The effect of temperature and magnetic feld onelectrical transport properties has been investigated. Bottom electrode and junction resistances were observed tostrongly depend on temperature. Large magnetoresistance of almost 300 % was observed at 77.3 K at low magneticfelds of a few tens of Oe. The large magnetoresistance was explained by the nearly half-metallic band structure ofLa0.7Sr0.3MnO3. The asymmetry of TMR curves was attributed to the ferromagnetic electrodes with different thickness and the differences in the electronic states of the upper and lower STO/LSMO interfaces

Keywords:

La0.7Sr0.3MnO3, magnetic tunnel junction, spintronics, tunnelling magnetoresistance,

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