X-ray and neutron diffraction on laser heated levitated samples:

successes and challenges

Sergey V. Ushakov, Alfred J. Pavlik, Alexandra Navrotsky

Richard J. K. Weber

Chris J. Benmore

Joerg C. Neuefeind

Ele

me

nts

min

sp

ecif

ic g

rav

ity

max melting temperature °C

2000 3000

carb

ides

inte

rmeta

llic

s

oxi

des

bo

rid

esn

itri

de

s

silic

ates

sulp

hid

essi

licid

es

20

10

7

5

3

2

30

Silic

ate

s

Sr SiO2 4

Ca SiO2 4

Mg SiO2 4

2000

2500

3000

3500

Su

lfid

es

CeS

ThS

HfS

Pr S3 4

PrS

Hf Si3 2

MoSi2

Mo Si5 3

Sil

icid

es

Ta Si5 3

W Si5 3

Zr Si5 3

Hf Si5 3

TaSi2

V Si5 3

C

W

Re

Os

Mo

Ru

Ir

Nb

BHf

Carb

ides

HfCTaC

NbC

ZrC

Ta C2

Ta C2

WCW C

2

ThC2

ThC

SiC

VC

MoC

PrC2

UC2

B C4

GdC2

V C2

Ni C3

La C2 3

Nit

rid

es

HfN

TaN

ZrNBN

TiN

UNThN

Nb N2

AlN

NbNVN

Th N2 3

Ta N2

Bo

rid

es

HfB2

TaB2

ZrB2

WB

TiB2

WB2

ZrB

Mn B3 4

Ta B3 4

UB4

LaB6

VB2

UB2

TaB

NdB

ThB4

Mo B2

CeB6

CrB

Ox

ides

ThO2

HfO2

UO2

ZrO2

MgO

CaO

BeO

Sc O2 3

Y O2 3

La O2 3

Al O2 3

Gd O2 3

Cr O2 3

MgAl O2 4

Re W3 2

Re Ti2 4 5

Mo Al3

OsTa3

HfMo2

Al Mo2

Inte

rMe

ReW

OsTi

IrTa

RuZr

WPt

Ir Nb3

Ir Ti3

Me

ltin

g T

em

pe

ratu

re,

°C

High temperature ceramics for aerospace and nuclear applications

Calculation of Phase Diagrams (CALPHAD) methods rely on thermodynamic data for compounds and their alloys / solid solutions

FactSage, MTDATA, PANDAT, MatCalc, JMatPro, Thermo-Calc

1980 1990 2000 2010

50

100

150 CALPhaD

first principles phase diagrams

Nu

mb

er

of

pu

blic

atio

ns

Year

Thermodynamic data from high-T diffraction

Molar volumes as a function of temperature

DV for solid state phase transitions

DSc for order - disorder transitions

In situ phase diagram determination

0.3

0.4

0.5

0.6

0.7

0.2

Laser flashRonchi et al. 1999

Ronchi et al. 1993

UO2UO2

T1

T

Nd-YAG

Nd-YAGT2

ME

LT

ING

W

Temperature, °C

He

at

cap

acit

y (

J/g

·K)

1600 2000 2400 2800 3200 3600 4000 4400 4800

10

15

20

Cp

/R

Phase transitions in RE2O3

Ho O2 3

Lu O2 3

Yb O2 3

Tm O2 3

Er O2 3Y O2 3

Dy O2 3

Tb O2 3

Gd O2 3

Eu O2 3

Sm O2 3

Pm O2 3

Nd O2 3

Pr O2 3

Ce O2 3

La O2 3

A

B

C

H

X

Liq

2000 2500Temperature, °C

Ionic radius R

E (C

N=6

), Å

3+

0.85

1.05

NSF DMR 1506229 Phase Transitions in RE2O3 above 2000 °C

Aerodynamic levitators with laser heating

SNS NOMAD BL1B

Joerg Neuefeind Chris Benmore

CO laser10.6 µm

2

X-ray beam0.139397 Å

Richard Weber

APS 6-ID-D

APS 6-ID-D SNS NOMAD BL1B

Aerodynamic levitators with laser heating

Samples preparation

Powder melting

Nd2O3 Er2O3

Levitation Microprobe

2 4 6 8 10

0.1 s exposure time 60 summed exposures Cubic ZrO2 T app = 2900 °C a = 5.283 Å

APS 6-ID-D 6 seconds collection time

6 seconds collection

XRD data collection CO laser10.6 µm

2

X-ray beam0.139397 Å

Bank 1

Bank 2

Bank 3

Bank 4

Bank 5

ND data collection

Levitated Y2O3 at RT 30 minutes

SNS NOMAD BL1B

Data Processing

Calibration at RT for every levitating bead

Integration with FIT2D, refinement with GSAS/ExpGUI, FullProf, GSAS-II

Le Bail refinement of cell parameters for high temperature H phases in Y2O3, Er2O3, Ho2O3

Refinement of room temperature structures on

levitated samples to validate the method

ND of levitated La2Zr2O7 at RT, BANK 3, Rietveld fit

a 10.8133(3)

x(O) 0.3305 (1)

100*UISO Å

La 0.65(4)

Zr 0.34(4)

O 0.84(3)

0.10(3)

χ2 2.75 Rwp 4.8% RF

2 4.3 %

Results from 3 days of diffraction experiments on levitator at APS (June 15-17, 2011)

Y2O3 transforms in H-type before melting in Ar and O2. Volume reduction on C-H phase transition was refined.

Pyrochlore structure of La2Zr2O7 persists to the melting temperature. Thermal expansion was used to validate high temperature ab initio calculations.

Thermal expansion of Eu2O3-ZrO2 DF solid solutions and anti-site occupancies on pyrochlore-DF phase transition in Eu2Zr2O7 were refined.

Maram PS, Ushakov SV, Weber RJK, Benmore CJ, & Navrotsky A (2015) J. Am. Ceram. Soc. 98 (4), 1292

Hong Q-J, Ushakov SV, Navrotsky A, & van de Walle A (2015) Acta Mater. 84, 275

Ushakov SV & Navrotsky A (2012) J. Am. Ceram. Soc. 95, 1463

CO laser10.6 µm

2

X-ray beam0.139397 Å

10.45

10.50

10.55

10.60

10.65

10.70

10.75

10.80

10.85

1000 2000 3000

a, Å

Temperature, °C

Lu2O3

Yb2O3

Er2O3

Ho2O3

4

5

6

7

8

9

10

11

12

TEC

, 10

-6/°

C

Lu2O3 Yb2O3 Er2O3 Ho2O3

Thermal expansion of C-type RE2O3 in Oxygen flow

Alfred Pavlik, Summer 2015

Pre-melting C-H phase transition in Er2O3 in Ar

H-type Z=1

C-type Z=16

Y2O3 DV -3.1% Er2O3 DV -3.4% Ho2O3 DV -3.9%

C-H pre-melting phase transitions RE2O3

Neutron Diffraction results (Aug 23-29, 2014)

Ushakov, S. V., Navrotsky, A., Weber, R. J. K. and Neuefeind, J. C. (2015), Structure and Thermal Expansion of YSZ and La2Zr2O7 Above 1500°C from Neutron Diffraction on Levitated Samples. J. Am. Ceram. Soc., 98: 3381

YSZ La2Zr2O7

0.31

0.32

0.33

0.34

0 500 1000 1500 2000 2500x

(O, 4

8f)

Temperature, °C

Conclusion

Refinement of high temperature structures is possible from X-ray and neutron diffraction on laser heated levitated samples using existing instruments at APS 6-ID-D and SNS NOMAD*

*Thermal gradient of ~150 °C in diffraction volume

http://thermo.ucdavis.edu/

Confirmed Invited speakers: Dario Manara, ITU Elizabeth Opila, University of Virginia Richard Weber, MDI Lawrie Skinner, Stony Brook

UC Davis workshop on

Structure and Thermodynamics of oxides at High Temperature

October 18-21, 2016 (before MS&T 2016 and ACerS 118th meeting in Salt Lake City)

Questions ?