Fabrication and Properties of MSMAThin Films

Hierarchical Manufacturing and Modeling Hierarchical Manufacturing and Modeling for Phase Transforming Active Nanostructuresfor Phase Transforming Active Nanostructures

D.C. Lagoudas a, K. Gall b, I. Karaman c, X. Zhang c, J. Kameoka d

a Department of Aerospace Engineering, Texas A&M University, College Station, Texas 77843-3141; b School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0250; c Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843-3123; d Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843-3128

Overall Concept

•Understand the effect of nanoscale manufacturing on reversible martensitic phase transformations

•Develop low-cost and easily scalable nanomanufacturing techniques that will allow fabrication of shape memory alloy (SMA) and magnetic shape memory (MSMA) alloy nanowires

•Fabricate higher scale structures and devices from nanowires and hybrid thin films

•Use multiscale modeling framework to guide the fabrication process, reveal fundamental multi-scale physical phenomena in reversible phase transformation, and aide design of higher scale devices

•Fabrication of nanofiber membrane for protein detection

Project Objectives

Fabrication of Monolithic and Hybrid SMA and MSMA Nanowire

Modeling In-21at%Tl bulk and nanowires

Developing new potentials based on ab initio calculations

• Graduate a diverse group of students prepared for research on nanotechnology with an interdisciplinary and global outlook

• Motivate undergraduates, particularly those from underrepresented groups, to continue to graduate school and research careers

• Educate undergraduate and K-12 students and teachers on technology, its benefits, and to communicate the excitement of discovery of science

Educational Goals

Nanowire Fabrication Procedure

Indium-Thallium (In-21at%Tl) Nanowires

Various diameters of In-21at%Tl nanowires fabricated (750nm, 380nm, 280nm, 70nm, 33nm). For nanowires of diameters >70nm, twins observed at room temperature along entire length of nanowires

Anodized Aluminum Oxide (AAO) Template (Empty)

Anodized Aluminum Oxide (AAO) Template (Empty)

Filled AAO template after extrusion

Filled AAO template after extrusion

In-21at%Tl Nanowires in Cross-Section of AAO

In-21at%Tl Nanowires in Cross-Section of AAO

123

1 2 3

TEM dark field image of 200nm diameter nanowire showing BCT twins

at room temperature

TEM Dark field image of 70nm diameter nanowire showing BCT twins

at room temperature

TEM Dark field image of 70nm diameter nanowire with constant

crystal structure at 100°C

TEM Dark field image of 33nm diameter nanowire at room

temperature

• For 70nm diameter nanowires, reversible phase transformation observed from BCT martensite to FCC austenite

• For 33nm diameter nanowires, SAED patterns indicate FCC crystal structure (austenite) at room temperature

Selected Area Electron Diffraction (SAED) patterns of 33nm diameter nanowire at room temperature

Multiscale Modeling Framework and Simulation

Multilayer twinned B19’Multilayer twinned B19’

3 Layers

2 Layers

• Surface energy will reduce as twin width increases • Agree well with the experimental observation• Surface energy will reduce as twin width increases • Agree well with the experimental observation

2]100[ B

2]011[ B

1/8[100] {011}

Shuffling

1/2[100] {011}

Shuffling

2]100[ B

2]011[ B

2]100[ B

2]011[ B

1/8[100] {011}

Shuffling

1/2[100] {011}

Shuffling

Compared with shuffling to B19Compared with shuffling to B19

one layer of atoms out of two layersone layer of atoms out of two layers

2

_

)011(101 B shuffling

two layers of atoms out of four layers

two layers of atoms out of four layers

2]011[ B

2]011[ B

• Fabricate In-21at%Tl nanowires of smaller diameter

• Fabricate NiMnCoIn nanowires from produced thin films

Future Work

Mechanical Arm

Mechanical Arm

Pressing ChamberPressing Chamber

Hydraulic Jack

Hydraulic Jack

Mold containingtemplate and

thin film

Mold containingtemplate and

thin film

Magnetron sputtering system for multilayer film depositions. The system has four magnetron guns capable of DC and RF sputtering and is able to obtain a base pressure of 10-8 Torr or better. A load lock is attached to the system to increase the throughput of the system.

Sputtering SystemSputtering System

NiMnCoIn Thin FilmsNiMnCoIn Thin Films

•DSC curve of an as deposited, amorphous freestanding Ni50Co6Mn38In6 film. The film was heated/cooled/heated at a rate of 80 °C/min. 0 100 200 300 400 500

418.25 °C

341.26 °C

450.45 °C

Exo

ther

mic

Temperature (°C)

•DSC curves of crystallization process in freestanding Ni50Co6Mn38In6 films heated linearly at different rates. The effective crystallization energy was calculated to be 86.59 kJ mol-1. 300 400 500

80 °C/min

40 °C/min

10 °C/min

20 °C/min

Exo

ther

mic

Temperature (°C)

5 °C/min

NiMnGa Thin FilmsNiMnGa Thin Films

NiMnGa Thin Films were deposited on several substrates. Mn-rich target with the composition of Ni49.5Mn30Ga20.5 was used. The composition was tailored by varying the deposition power.

NiMnGa Thin Films were deposited on several substrates. Mn-rich target with the composition of Ni49.5Mn30Ga20.5 was used. The composition was tailored by varying the deposition power.

The as-deposited films were partly crystalline as seen in the xrd pattern

The as-deposited films were partly crystalline as seen in the xrd pattern

RTRT Above AfAbove Af

Below MfBelow Mf

The DSC plot shows reversible martensite to austenite phase transformation 

The DSC plot shows reversible martensite to austenite phase transformation 

As-deposited film shows grains with needle shaped texture indicatingmartensite, distributed in a seemingly amorphous matrix. Above A f, the diffraction pattern shows a significant change in SADP along with grain growth. Change in SADP was again observed when cooled below M f

As-deposited film shows grains with needle shaped texture indicatingmartensite, distributed in a seemingly amorphous matrix. Above A f, the diffraction pattern shows a significant change in SADP along with grain growth. Change in SADP was again observed when cooled below M f

Nanoscale Martensitic Transformation Mechanisms in NiTiNanoscale Martensitic Transformation Mechanisms in NiTi

Fabrication of Nanofiber Membrane for Protein Detection

•Solution: a mixture of spin on glass coating (SOG), polyvinylpyrrolidone (PVP), and butanol.

•Solution concentration: PVP 0.04 g/ml, SOG:butanol = 4:1 in volume ratio.

•Processing parameters: feeding rate: 8 ul/min, applied voltage: 7 kV, deposition distance: 5 cm, heating temperature: 500°C for 12h.

•PVP was removed during the heating. Resultant silica membrane was composed of nanofiber with ~100 nm in diameter.

Electrospinning of Silica Nanofiber Membrane

Performance of Protein Detection

SEM image of silica spun nanofibers

Schematic of nanofiber membrane protein detector

•Random-distributed electrospun nanofibers formed a porous membrane. The membrane is incorporated in the layered structure of the detector.

•The sensitivity is improved due to the small diameter of nanofibers and the resultant extremely large surface area to volume ratio.

•The detection limit is 32 times lower than traditional 96-well enzyme-linked immunosorbent assay (ELISA).

•The detection time is 1h compared to ELISA’s 1 day