Correlation between magneto-optical and transport properties of Sr doped manganite films

Abstract

The features of electronic structure of La0.7Sr0.3MnO3, Pr0.8Sr0.2MnO3, and Pr0.6Sr0.4MnO3 polycrystalline films of different thickness have been investigated using magnetic circular dichroism (MCD) in the range of 1.1-4.2 eV. The temperature behavior of the samples electrical resistance were also has been studied. It was found that films with high Sr content (0.3 and 0.4) act as hightemperature semiconductors, while the maximum in the temperature dependences of these films resistivity indicates the transition of the samples to the metallic state at some temperature TM-S, which is different for different sample thickness. The films with the lower Sr content (0.2) act as insulators in the used temperature range. The MCD spectra have been decomposed to the Gaussian-shaped lines, and the temperature dependence of intensity of each line has been analyzed in comparison with temperature dependence of the films magnetization and with their electric conductivity type. Different temperature behavior of the intensity of four specified Gaussian-lines was revealed for semiconductor films. In the case of insulating Pr0.8Sr0.2MnO3 samples, the intensity of three specified Gaussian lines changes with the temperature in the same way as the magnetization changed. It was established that the lanthanide (La, Pr) type does not affect the MCD spectra shape for the films with the same electrical conductivity type. Besides, the correlation between the MCD data of the films and their conductivity type was revealed. Due to the detailed analysis of the specified Gaussian lines with taking into account the well-known in the literature absorption bands, lying outside the studied spectral region, the MCD bands for the studied manganite films have been identified with electronic transitions of a different nature.

Strain-induced charge ordering above room temperature in rare-earth manganites

“…Dalton Transactions the same time, the La 0.7 Sr 0.3 MnO 3 and Pr 0.6 Sr 0.4 MnO 3 films undergo a metal-insulator transition near T C . 33 The temperature variation of the resistivity of Pr 0.8 Sr 0.2 MnO 3 films indicates their dielectric state over the entire temperature range. As the samples thickness decreases, the metal-semiconductor transition temperature (T MI ) decreases within 20 K. This behavior may indicate a slight decrease in the crystallite sizes in the films with decreasing thickness.…”

Особенности поглощения тонких пленок La-=SUB=-0.69-=/SUB=-Ba-=SUB=-0.31-=/SUB=-MnO-=SUB=-3-delta-=/SUB=-, полученных методом импульсного лазерного осаждения

“…Исследования магнитооптических (МО) эффектов в сильнокоррелированных соединениях на основе допированных манганитов лантана обычно ограничиваются эффектами Фарадея и Керра, магнитного кругового или линейного дихроизма в области фундаментального поглощения и диапазоном температур вблизи магнитного фазового перехода ферромагнетик/парамагнетик, который, как правило, находится ниже комнатной температуры [1][2][3]. Внешнее магнитное поле влияет на процессы взаимодействия света с примесными состояниями, локализованными и делокализованными носителями заряда в инфракрасном (ИК) диапазоне, что дает основной вклад в магнитотранспортные и МО свойства допированных манганитов.…”

Features of absorption of thin films La-=SUB=-0.69-=/SUB=-Ba-=SUB=-0.31-=/SUB=-MnO-=SUB=-3-delta-=/SUB=- obtained using the method of pulsed laser deposition

“…Studies of magneto-optical (MO) effects in strongly correlated compounds based on doped lanthanum manganites are usually limited by the Faraday and Kerr effects, magnetic circular or linear dichroism in the fundamental absorption region, and the temperature range near the ferromagnet/paramagnet magnetic phase transition, which, as a rule, is below room temperature [1][2][3]. An external magnetic field affects the processes of interaction of light with impurity states, localized and delocalized charge carriers in the infrared (IR) range, which makes the main contribution to the magnetotransport and MO properties of doped manganites.…”