Structural and magnetic phase transitions in chromium nitride thin films grown by rf nitrogen plasma molecular beam epitaxy

Journal Article · Fri Sep 01 00:00:00 EDT 2017 · Physical Review. B

DOI:https://doi.org/10.1103/physrevb.96.104433· OSTI ID:1535999

Alam, Khan ^[1]; Disseler, Steven M. ^[2]; Ratcliff, William D. ^[2]; Borchers, Julie A. ^[2]; Ponce-Pérez, Rodrigo ^[3]; Cocoletzi, Gregorio H. ^[4]; Takeuchi, Noboru ^[5]; Foley, Andrew ^[1]; Richard, Andrea ^[1]; Ingram, David C. ^[1]; Smith, Arthur R. ^[1]

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1. Ohio Univ., Athens, OH (United States). Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy
2. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). NIST Center for Neutron Research
3. Ohio Univ., Athens, OH (United States). Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy; Instituto de Fısica, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
4. Instituto de Fısica, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
5. Ohio Univ., Athens, OH (United States). Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy; Centro de Nanociencias y Nanotecnologıa, Universidad Nacional Autonoma de Mexico, Ensenada, Mexico

A magneto-structural phase transition is investigated in single crystal CrN thin films grown by rf plasma molecular beam epitaxy on MgO(001) substrates. While still within the vacuum environment following MBE growth, in-situ low-temperature scanning tunneling microscopy, and in-situ variable low-temperature reflection high energy electron diffraction are applied, revealing an atomically smooth and metallic CrN(001) surface, and an in-plane structural transition from 1×1 (primitive CrN unit cell) to $$\sqrt{2}$$ × $$\sqrt{2}$$ -R45° with a transition temperature of 278 ± 3 K, respectively. Ex-situ temperature dependent measurements using neutron diffraction are also per formed, looking at the structural peaks and likewise revealing a first-order structural transition along the [111] out-of-plane direction, with a transition temperatures of 268 ± 3 K. Turning to the magnetic peaks, neutron diffraction confirms a clear magnetic transition from paramagnetic at room temperature to antiferromagnetic at low temperatures with a sharp, first-order phase transition and a Néel temperature of 270 ± 2 K or 280 ± 2 K for two different films. In addition to the experimental measurements of structural and magnetic ordering, we also discuss results from first-principles theoretical calculations which explore various possible magneto-structural models.

• Research Organization: Ohio Univ., Athens, OH (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: FG02-06ER46317
• OSTI ID: 1535999
• Alternate ID(s): OSTI ID: 1394692
• Journal Information: Physical Review. B, Vol. 96, Issue 10; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

Materials Science
Physics