Unraveling the resistive switching response of Metal / La1-xSrxMnO3 / Pt devices


Recently, resistive random access memories (ReRAM) have generated significant interest both in industry and in the scientific community for their use as non-volatile memory beyond Flash memory scaling. ReRAMs are considered one of the most promising emerging non-volatile memories due to high speed, high density, great scalability and low power consumption. Recent work carried out in the group has pointed out towards strontium-substituted lanthanum manganite (LSM) as an attractive switching material. The goal of this project is to investigate electrode/LSM heterostructures with various substitution levels in order to control and optimize their electrical response. A number of different electrical measurements will be designed and carried out to characterize the devices’ static and dynamic (resistive switching) electrical response. The results will be key to understand and develop innovative ReRAM structures.

Project description

Manganite heterostructures show very promising resistive switching (RS) characteristics and multilevel resistance states. This makes them ideal candidates for alternative non-volatile memories, but also as building blocks for neuromorphic computation. In contrast to the more common filamentary switching, manganite devices have been shown to switch homogeneously over the whole device area and might therefore be superior with respect to their cell-to-cell and cycle-to-cyclevariation. A memristive device is best described as a capacitor-like heterostructure where an oxide material is sandwiched between two electrodes (see Figure 1.a). By applying a voltage to one of the electrodes internal redox reactions occur, which induce switching between resistance states. The typical current-voltage curve for a RS memory cell is shown in Figure 1.b.
The Master student will focus on the investigation of the resistive switching characteristics of LSM heterostructures in the framework of the ongoing Mangaswitch project. The main objectives of this internship are: 1) characterize the structural materials properties of different heterostructures and 2) to perform the complete electrical characterization of these top electrode/oxide/Pt heterostructures. Combining all these results we aim to understand the fundamental mechanisms responsible for the RS in these devices, i.e. to understand the physico-chemical, structural and micro-structural processes taking place during device operation and to relate them to the measured electrical characteristics.
LMGP houses state of the art experimental equipment for investigating such properties. This equipment will be used in combination with electrical measurements to characterize the heterostructures in view of getting a better understanding of the relationship between microstructure and memory properties.

Scientific environment:

The candidate will work within the LMGP, Materials and Physical Engineering Laboratory, in the Oxides for Nanoionic Devices group (https://lmgp.grenoble-inp.fr/en/research/oxides-for-nanoionic-devices) within the Nanomat Team.
Located in the heart of an exceptional scientific environment, the LMGP offers the applicant a rewarding place to work.
LMGP Web Site: http://www.lmgp.grenoble-inp.fr/

Profile & requested skills:

We are looking for a highly-motivated Engineering School or M2 Masters student with a strong interest in experimental physics and materials science. Interpersonal skills, dynamism, rigor and teamwork abilities will be appreciated. Candidates should have good English writing and speaking skills. Group meetings and supervision will be in English.
Subject could be continued with a PhD thesis: Potentially in related topic