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Accelerated Discovery of i-MAX Phases

via HT-DFT Calculations

Ruijie Zhu

09/27/2022

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About me

I love hackathons and long distance running!

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What are MAX phases?

MAX phases are layered transition metal carbides and/or nitrides

211

312

413

hexagonal lattice

SG: P63/mmc

View along c axis

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Properties of MAX phases

High mechanical strength
High electrical conductivity
Resistance to oxidation and corrosion

Barsoum, Michel W., and Miladin Radovic. "Elastic and mechanical properties of the MAX phases." Annual review of materials research 41 (2011): 195-227.

Barsoum, M. W., et al. "Electrical conductivity, thermopower, and hall effect of Ti 3 AlC 2, Ti 4 AlN 3, and Ti 3 SiC 2." Physical Review B 62.15 (2000): 10194.

Fu, Jianjian, et al. "Oxidation and corrosion behavior of nanolaminated MAX-phase Ti2AlC film synthesized by high-power impulse magnetron sputtering and annealing." Journal of Nanomaterials 2015 (2015).

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i-MAX Phases

In-plane ordered MAX Phases

(M_2/3M’_1/3)₂AX

C2/c

Cmcm

M’

Two Polymorphs

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Experimentally synthesized i-MAX phases

(Mo_2/3Sc_1/3)₂AlC
(Mo_2/3Sc_1/3)₂GaC
(Mo_2/3Y_1/3)₂AlC
(Mo_2/3Y_1/3)₂GaC
(Cr_2/3Sc_1/3)₂AlC
(Cr_2/3Sc_1/3)₂GaC
(Cr_2/3Y_1/3)₂AlC

(Cr_2/3Zr_1/3)₂AlC
(V_2/3Zr_1/3)₂AlC
(V_2/3Sc_1/3)₂AlC
(W_2/3Sc_1/3)₂AlC
(W_2/3Y_1/3)₂AlC
(Mn_2/3Sc_1/3)₂GaC

(Mo_2/3Ce_1/3)₂AlC
(Mo_2/3Pr_1/3)₂AlC
(Mo_2/3Nd_1/3)₂AlC
(Mo_2/3Sm_1/3)₂AlC
(Mo_2/3Gd_1/3)₂AlC
(Mo_2/3Tb_1/3)₂AlC
(Mo_2/3Dy_1/3)₂AlC

(Mo_2/3Ho_1/3)₂AlC
(Mo_2/3Er_1/3)₂AlC
(Mo_2/3Tm_1/3)₂AlC
(Mo_2/3Lu_1/3)₂GaC
(Mo_2/3Gd_1/3)₂GaC
(Mo_2/3Tb_1/3)₂GaC
(Mo_2/3Dy_1/3)₂GaC

(Mo_2/3Ho_1/3)₂GaC
(Mo_2/3Er_1/3)₂GaC
(Mo_2/3Tm_1/3)₂GaC
(Mo_2/3Yb_1/3)₂GaC
(Mo_2/3Lu_1/3)₂GaC
(W_2/3Gd_1/3)₂AlC
(W_2/3Tb_1/3)₂AlC

(W_2/3Dy_1/3)₂GaC
(W_2/3Ho_1/3)₂GaC
(W_2/3Er_1/3)₂GaC
(W_2/3Tm_1/3)₂GaC
(W_2/3Lu_1/3)₂GaC

without RE elements

with RE elements

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Stability of Experimental Compounds

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Elements Used For Prototype Decoration

M/M’

Ternary MAX phases: 1560 combinations

i-MAX phases: 7774 combinations

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Calculation Summary

Quaternary i-MAX phases

Ternary MAX phases

type	total	stable compounds	stable carbides	stable nitrides
211	520	51	41	10
312	520	47	42	5
413	520	32	13	19

total	stable compounds	stable carbides	stable nitrides
7774	331	292	39
non-experimental	295	256	39

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Ehull distribution of i-MAX Phases

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experimentally synthesized

Stability Heatmaps

carbides

M-M’-A-C

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Stability Heatmaps

nitrides

M-M’-A-N

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Most experimental compounds are on the convex hull, except for Mo_1.33Yb_0.67GaC
A total of 331 i-MAX phases were found to be stable at 0K, 295 of which have not been experimentally synthesized
In general, Ga- and Al-containing compounds are the most stable, followed by In- and Zn-containing compounds

Conclusions