In 2013, a new class of inherently nanolaminated magnetic materials, the so called magnetic MAX phases, was discovered. Following predictive material stability calculations, the hexagonal Mn 2 GaC compound was synthesized as hetero-epitaxial films containing Mn as the exclusive M-element. Recent theoretical and experimental studies suggested a high magnetic ordering temperature and non-collinear antiferromagnetic (AFM) spin states as a result of competitive ferromagnetic and antiferromagnetic exchange interactions. In order to assess the potential for practical applications of Mn 2 GaC, we have studied the temperature-dependent magnetization, and the magnetoresistive, magnetostrictive as well as magnetocaloric properties of the compound. The material exhibits two magnetic phase transitions. The Néel temperature is T N ~ 507 K, at which the system changes from a collinear AFM state to the paramagnetic state. At T t = 214 K the material undergoes a first order magnetic phase transition from AFM at higher temperature to a non-collinear AFM spin structure. Both states show large uniaxial c-axis magnetostriction of 450 ppm. Remarkably, the magnetostriction changes sign, being compressive (negative) above T t and tensile (positive) below the T t . The sign change of the magnetostriction is accompanied by a sign change in the magnetoresistance indicating a coupling among the spin, lattice and electrical transport properties.Inherently nanolaminated M n+1 AX n (n = 1, 2, 3) compounds attract tremendous interest, since these materials provide the unique anisotropic structural and physical properties important for diverse applications 1,2 . These compounds, collectively known as MAX phases, are composed of an early transition metal (M), a p-element from the A-group elements (A) and X being either C or N. MAX phases have a hexagonal structure and belong to the space group P6 3 /mmc with the primitive unit cell given by 8 atoms: 4 M, 2 A and 2 X (for n = 1). These systems exhibit an atomically laminated structure composed of M-X-M (M 2 X) slabs interleaved by A-element atomic layers. The atomic layers are stacked along the c-axis. The layered, highly anisotropic crystal structure results in mechanical properties usually associated with ceramics, such as high stiffness, damage tolerance and resistance to corrosion and thermal shock 1,2 . The chemical bonding of the M, A and X elements is anisotropic and comprises metallic, covalent and ionic character 2 . The strong hybridization between d orbitals of the M-element and 2p states of the X-element results in directed covalent bonds along the M-X-M chains in basal planes 2,3 . The M-A bonding is generally weaker and accompanied by partial charge transfer from the M-element to the A-element, giving rise to the ionic contribution 2-4 . Metallic-like bonding between d states of the M-element occurs in the
