In situ TEM observations of irradiation-induced phase change in tungsten

2009 ◽  
Vol 44 (8) ◽  
pp. 1965-1968 ◽  
Author(s):  
C. L. Chen ◽  
T. Nagase ◽  
H. Mori
Keyword(s):  
Phase Change ◽  
In Situ Tem

scholarly journals In situ TEM observation of void formation and migration in phase change memory devices with confined nanoscale Ge2Sb2Te5

2020 ◽  
Vol 2 (9) ◽  
pp. 3841-3848
Author(s):  
Sang Ho Oh ◽  
Kyungjoon Baek ◽  
Sung Kyu Son ◽  
Kyung Song ◽  
Jang Won Oh ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Memory ◽  
Void Formation ◽  
In Situ Tem ◽  
Memory Devices ◽  
Device Failure ◽  
And Migration ◽  
Change Memory

Void formation and migration that drive the device failure of Ge2Sb2Te5 (GST)-based practical devices were revealed via in situ TEM.

In-situ Characterization of Switching Mechanism in Phase Change Random Access Memory (PRAM) Using Transmission Electron Microscopy (TEM)

2013 ◽  
Author(s):  
Sungkyu Son ◽  
Seungjoon Jeon ◽  
Jangwon Oh ◽  
Won Kim ◽  
Hojoung Kim ◽  
...  
Keyword(s):  
Phase Transition ◽  
Failure Analysis ◽  
Phase Change ◽  
Void Formation ◽  
Amorphous State ◽  
Random Access ◽  
Switching Behavior ◽  
In Situ Tem ◽  
Switching Mechanism

Abstract It is important to understand the switching mechanism of phase change material for failure analysis of PRAM device. In this study, the real time observations of phase transition and void formation mechanism of confined GST structure were investigated using in-situ TEM with multi-pulse AC biasing technique. In-situ SET switching behavior between amorphous state and crystalline state with continuous structural change was successfully observed. Volume shrink of GST, due to the phase transition, induced voids at grain boundary of crystalline phase. Excess Joule-heating after crystallization caused coalescence and migration of voids. These results may give us a crucial clue for endurance failure analysis of PRAM.

scholarly journals In-Situ TEM Observation of Crystallization in Phase-Change Material

2018 ◽  
Vol 24 (S1) ◽  
pp. 1930-1931 ◽  
Author(s):  
Khim Karki ◽  
Victoriea L. Bird ◽  
Daan Hein Alsem ◽  
Melissa K. Santala
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
In Situ Tem ◽  
Change Material

scholarly journals Microstructure-dependent DC set switching behaviors of Ge–Sb–Te-based phase-change random access memory devices accessed by in situ TEM

2015 ◽  
Vol 7 (6) ◽  
pp. e194-e194 ◽  
Author(s):  
Kyungjoon Baek ◽  
Kyung Song ◽  
Sung Kyu Son ◽  
Jang Won Oh ◽  
Seung-Joon Jeon ◽  
...  
Keyword(s):  
Phase Change ◽  
Random Access ◽  
Random Access Memory ◽  
In Situ Tem ◽  
Memory Devices ◽  
Access Memory ◽  
Set Switching

scholarly journals In-situ TEM Investigation of the Amorphous to Crystalline Phase Change During Electrical Breakdown of Highly Conductive Polymers at the Atomic Scale

2020 ◽  
Vol 26 (S2) ◽  
pp. 3198-3200
Author(s):  
Michele Conroy ◽  
Kalani Moore ◽  
Rob Lehane ◽  
Alonso Gamero-Quijano ◽  
Micheal Scanlon ◽  
...  
Keyword(s):  
Phase Change ◽  
Crystalline Phase ◽  
Conductive Polymers ◽  
Electrical Breakdown ◽  
Atomic Scale ◽  
In Situ Tem

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

In situ TEM observations of melting in nanosized eutectic Pb-Cd inclusions embedded in Al

1996 ◽  
Vol 54 ◽  
pp. 986-987
Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev
Keyword(s):  
Electron Microscope ◽  
Melt Spinning ◽  
Ternary Alloys ◽  
Solid Matrix ◽  
Eutectic System ◽  
In Situ Tem ◽  
In Situ Observation ◽  
Orientation Relationships ◽  
Transmission Electron

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.

Sign in / Sign up

Export Citation Format

Share Document