Method of coating a substrate so as to provide a controlled in-plane compositional modulation, comprising: providing a first target (103, 203, 303) of a first material or material composition, providing a second target (104, 204, 304) of a second material or material composition, different from the first material or material composition; activating the first and second targets (103, 104; 203 204; 303, 304) to release particles by evaporation, sublimation or sputtering; and causing the released particles to impinge onto the substrate (102, 202, 302) such that the substrate is coated; and wherein activation of one of the targets (103, 104; 203 204; 303, 304) includes providing a series of activation pulses, such that pulsed evaporation, sublimation or sputtering of particles is provided, while the other one of the targets (103, 104; 203 204; 303, 304) is substantially passive; wherein the first and second target materials or material compositions present: a respective homologous temperature, defined as a ratio (T s /T m i) of the substrate temperature (Ts) to the target material melting temperature (T m i) of the target material (i) having the lowest melting temperature (T m i), a miscibility (ΔH mix), as defined by a mixing enthalpy of the target materials or material compositions, wherein the mixing enthalpy of the materials greater than zero is defined as immiscible and a mixing enthalpy of the materials less than zero is defined as miscible; wherein the target materials present two-dimensional growth, wherein the homologous temperature is greater than 0.1 and less than 0.4, preferably less than 0.3 or less than 0.2; wherein the amount of material deposited per pulse train from each target material is greater than 0.1 monolayer and less than 2 monolayers, and wherein the target materials are immiscible. providing a first target (103, 203, 303) of a first material or material composition, providing a second target (104, 204, 304) of a second material or material composition, different from the first material or material composition; activating the first and second targets (103, 104; 203 204; 303, 304) to release particles by evaporation, sublimation or sputtering; and causing the released particles to impinge onto the substrate (102, 202, 302) such that the substrate is coated; and wherein activation of one of the targets (103, 104; 203 204; 303, 304) includes providing a series of activation pulses, such that pulsed evaporation, sublimation or sputtering of particles is provided, while the other one of the targets (103, 104; 203 204; 303, 304) is substantially passive; wherein the first and second target materials or material compositions present: a respective homologous temperature, defined as a ratio (T s /T m i) of the substrate temperature (Ts) to the target material melting temperature (T m i) of the target material (i) having the lowest melting temperature (T m i), a miscibility (ΔH mix), as defined by a mixing enthalpy of the target materials or material compositions, wherein the mixing enthalpy of the materials greater than zero is defined as immiscible and a mixing enthalpy of the materials less than zero is defined as miscible; wherein the target materials present two-dimensional growth, wherein the homologous temperature is greater than 0.1 and less than 0.4, preferably less than 0.3 or less than 0.2; wherein the amount of material deposited per pulse train from each target material is greater than 0.1 monolayer and less than 2 monolayers, and wherein the target materials are immiscible. a respective homologous temperature, defined as a ratio (T s /T m i) of the substrate temperature (Ts) to the target material melting temperature (T m i) of the target material (i) having the lowest melting temperature (T m i), a miscibility (ΔH mix), as defined by a mixing enthalpy of the target materials or material compositions, wherein the mixing enthalpy of the materials greater than zero is defined as immiscible and a mixing enthalpy of the materials less than zero is defined as miscible; wherein the target materials present two-dimensional growth, wherein the homologous temperature is greater than 0.1 and less than 0.4, preferably less than 0.3 or less than 0.2; wherein the amount of material deposited per pulse train from each target material is greater than 0.1 monolayer and less than 2 monolayers, and wherein the target materials are immiscible.