Ce0.8Gd0.2O2‐δ / La0.6Sr0.4CoO3 Heterostructures prepared by pulsed laser deposition

Dos-Santos-Gómez, Lucía; Porras-Vázquez, José Manuel; Ramírez-Losilla, Enrique; Marrero-López, David

Abstract

Oxide interfaces have received greater attention due to the possibility to obtain properties that are very different from bulk materials. Due to the wide variety of electronic and ionic phenomena than can be detected at the interfaces, such materials have many technological applications [1]. Attention is being drawn to oxide heterostructures, a new family of artificial materials where electronic and ionic properties can be modulated at the interfaces by varying the characteristics of the layers [2, 3]. Slight variations in the near anionic-cationic order might take place if there exists strained interfaces. The interest in multilayared heterostructures derives from the mobility deffects and the space-charge-zone effects at the interfaces. In addition, a new degree of freedom related to the capacitive and resistive contributions is provided as a consequence of the size effects of these artificial structures. In the present work, for the first time, we investigate the structure, microstructure and electrical properties of a new family of heterostructured materials with alternated thin layers of La0.6Sr0.4CoO3 (LSC) and Ce0.8Gd0.2O2-δ (CGO) deposited by pulsed laser deposition on (110) NdGaO3 (NGO) single crystal substrates. In order to evaluate the interfacial contribution to ionic-electronic conductivity and know what is actually happens at the interface of MIECs, different heterostructures were prepared by varying both the number of bilayers (N) and the total thickness of the samples (N = 2 and 5; and the thickness were 50, 100 and 300 nm).

Ce0.8Gd0.2O2‐δ / La0.6Sr0.4CoO3 Heterostructures prepared by pulsed laser deposition

Author: Dos-Santos-Gómez, Lucía,Porras-Vázquez, José Manuel,Ramírez-Losilla, Enrique,Marrero-López, David

Year: 2018

Source: https://riuma.uma.es/xmlui/bitstream/10630/16454/4/ECM31.pdf

Ce0.8Gd0.2O2-δ / La0.6S 0.4CoO3 he e os uc u es p epa ed by
pulsed lase deposi ion.
Lucía dos San os-Gómez, José Manuel Po as-Vázquez, En ique R. Losilla, Da id Ma e o-López
KEYWORDS: He e os u c u es, Ce0.8Gd0.2O2-δ, La0.6S 0.4CoO3-δ.
Oxide in e aces ha e ecei ed g ea e a en ion due o he possibili y o ob ain
p ope ies ha a e e y di e en om bulk ma e ials. Due o he wide a ie y o elec onic
and ionic phenomena han can be de ec ed a he in e aces, such ma e ials ha e many
echnological applica ions [1]. A en ion is being d awn o oxide he e os uc u es, a new amily
o a i icial ma e ials whe e elec onic and ionic p ope ies can be modula ed a he in e aces
by a ying he cha ac e is ics o he laye s [2, 3]. Sligh a ia ions in he nea anionic-ca ionic
o de migh ake place i he e exis s s ained in e aces. The in e es in mul ilaya ed
he e os uc u es de i es om he mobili y de ec s and he space-cha ge-zone e ec s a he
in e aces. In addi ion, a new deg ee o eedom ela ed o he capaci i e and esis i e
con ibu ions is p o ided as a consequence o he size e ec s o hese a i icial s uc u es.
In he p esen wo k, o he i s ime, we in es iga e he s uc u e, mic os uc u e and
elec ical p ope ies o a new amily o he e os uc u ed ma e ials wi h al e na ed hin laye s
o La0.6S 0.4CoO3 (LSC) and Ce0.8Gd0.2O2-δ (CGO) deposi ed by pulsed lase deposi ion on (110)
NdGaO3 (NGO) single c ys al subs a es. In o de o e alua e he in e acial con ibu ion o
ionic-elec onic conduc i i y and know wha is ac ually happens a he in e ace o MIECs,
di e en he e os uc u es we e p epa ed by a ying bo h he numbe o bilaye s (N) and he
o al hickness o he samples (N = 2 and 5; and he hickness we e 50, 100 and 300 nm).
The quali y o he samples was examined by HR-TEM and all o hem p esen ed well
de ined in e aces. The ocking cu e and HR-TEM images indica e ha he CGO cells a e
o a ed 45º wi h espec o NGO and LSC ones as can be obse ed in he igu e. In addi ion,
due o he g ea la ice misma ch be ween NGO, CGO and LSC, he asymme ic e lec ions o
(113) plane can be dis inguished in he ecip ocal space mapping and he analysis o hese
esul s indica es ha he in e aces gene a e a comp essi e s ain in CGO laye s and,
consequen ly, ensile s ain in he LSC ones. Conduc i i y o CGO/LSC he e os uc u es is
a ec ed by he hickness and he numbe o in e aces in he he e os uc u e, and he
hickness is he dominan ac o in he conduc i i y a ia ion.
REFERENCIAS:
[1] P yds, N. & Esposi o, V. (2017). J. Elec oce am. 38, 1-23.
[2] Sanna, S. e al. (2010). Small. 6, 1863-1867.
[3] Schweige , S. e al. (2014). ACS Nano. 8, 5032-5048.